[OnePlus 5T  Guides, News, & Discussion] Dior DNA:
About duplicate votes (meaning same voter voted 'accidentally' same firmware):

Currently (May 10 22:00 CET), out of 529 votes, 16 are duplicate.

One brave person voted for 12 different ROMs ! (not duplicates)

1 person voted 'OmniRom' 6 times
1 person voted 'Codename Phoenix' 3 times
3 persons voted 'Codename Phoenix' 2 times
2 persons voted 'OxygenOS Official' 2 times
1 person voted 'Dirty Unicorns' 2 times
1 person voted 'MicroG LineageOS' 2 times
1 person voted 'Validus' 2 times

The results with duplicates are

137 "OxygenOS Open Beta"
116 "OxygenOS Official"
51 "Codename Phoenix"
29 "OmniRom"
28 "LineageOS Official"
24 "Resurrection Remix-OS"
23 "Liquid Remix"
16 "FrankenRom"
16 "Dirty Unicorns"
14 "crDroid"
13 "Zoe ROM"
10 "xXx_NoLimits"
7 "Treskmod"
6 "theOne5TOS"
5 "GZOSP Unofficial"
5 "Android Open Source Illusion Project"
5 "Android Ice Cold Project"
4 "Hydrogen OS"
3 "MicroG LineageOS"
3 "Bootleggers"
3 "AOSP-Extended"
2 "Validus"
2 "Screwd Rom"
1 "MSM Xtended"
1 "MoKee ROM Project Treble"
1 "LineageOS kylothow"
1 "Audax Rom"
1 "AquariOS"
1 "AOSCP"
1 "AEX Unofficial"

The results without duplicates are

137 "OxygenOS Open Beta"
114 "OxygenOS Official"
46 "Codename Phoenix"
28 "LineageOS Official"
24 "Resurrection Remix-OS"
24 "OmniRom"
23 "Liquid Remix"
16 "FrankenRom"
15 "Dirty Unicorns"
14 "crDroid"
13 "Zoe ROM"
10 "xXx_NoLimits"
7 "Treskmod"
6 "theOne5TOS"
5 "GZOSP Unofficial"
5 "Android Open Source Illusion Project"
5 "Android Ice Cold Project"
4 "Hydrogen OS"
3 "Bootleggers"
3 "AOSP-Extended"
2 "Screwd Rom"
2 "MicroG LineageOS"
1 "Validus"
1 "MSM Xtended"
1 "MoKee ROM Project Treble"
1 "LineageOS kylothow"
1 "Audax Rom"
1 "AquariOS"
1 "AOSCP"
1 "AEX Unofficial"

The results without duplicates per country are

98 "United States"
72 "India"
39 "Sweden"
34 "Germany"
20 "Canada"
18 "United Kingdom"
18 "Spain"
17 "France"
13 "Italy"
12 "Brazil"
12 "Australia"
11 "Romania"
10 "Belgium"
9 "Turkey"
9 "Poland"
8 "Netherlands"
7 "Singapore"
7 "Russian Federation"
7 "Finland"
6 "Portugal"
6 "Indonesia"
6 "Greece"
6 "China"
5 "Israel"
5 "Austria"
4 "Mexico"
4 "Malaysia"
4 "Korea
3 "Denmark"
3 "Czech Republic"
2 "Thailand"
2 "Saudi Arabia"
2 "Philippines"
2 "Norway"
2 "New Zealand"
2 "Mauritius"
2 "Bulgaria"
2 "Argentina"
1 "Tunisia"
1 "Switzerland"
1 "South Africa"
1 "Panama"
1 "Palestinian Territory
1 "Pakistan"
1 "Nepal"
1 "Luxembourg"
1 "Latvia"
1 "Kuwait"
1 "Kenya"
1 "Japan"
1 "Jamaica"
1 "Ireland"
1 "Iraq"
1 "Hungary"
1 "Hong Kong"
1 "Honduras"
1 "Ecuador"
1 "Cyprus"
1 "Colombia"
1 "Cape Verde"
1 "Bosnia and Herzegovina"
1 "Bangladesh"
1 "Armenia"

Countries by firmware

AEX Unofficial
1 India
================
Android Ice Cold Project
3 India
1 United States
1 France
================
Android Open Source Illusion Project
2 United States
1 India
1 Brazil
1 Australia
================
AOSCP
1 India
================
AOSP-Extended
1 United States
1 United Kingdom
1 India
================
AquariOS
1 United States
================
Audax Rom
1 Kuwait
================
Bootleggers
2 United States
1 India
================
Codename Phoenix
9 United States
7 India
3 United Kingdom
3 Spain
3 France
3 Canada
2 Sweden
2 Germany
2 Belgium
1 Portugal
1 Poland
1 Netherlands
1 Korea
1 Kenya
1 Italy
1 Finland
1 Bulgaria
1 Brazil
1 Bosnia and Herzegovina
1 Austria
1 Australia
================
crDroid
3 United States
2 India
1 Turkey
1 Thailand
1 Singapore
1 Russian Federation
1 Germany
1 France
1 Denmark
1 Belgium
1 Australia
================
Dirty Unicorns
4 United States
2 India
2 Germany
2 Canada
1 United Kingdom
1 Turkey
1 Sweden
1 Mexico
1 Israel
================
FrankenRom
6 United States
2 India
2 Germany
1 Tunisia
1 Spain
1 Singapore
1 Israel
1 Indonesia
1 China
================
GZOSP Unofficial
2 India
1 Singapore
1 Belgium
1 Australia
================
Hydrogen OS
2 United States
1 Denmark
1 Colombia
================
LineageOS kylothow
1 Russian Federation
================
LineageOS Official
6 United States
6 Germany
3 India
2 Sweden
2 France
2 Finland
2 Austria
1 Russian Federation
1 Netherlands
1 Indonesia
1 Belgium
1 Armenia
================
Liquid Remix
11 United States
3 India
2 Indonesia
2 France
1 United Kingdom
1 Honduras
1 Canada
1 Belgium
1 Australia
================
MicroG LineageOS
2 Sweden
================
MoKee ROM Project Treble
1 United States
================
MSM Xtended
1 India
================
OmniRom
5 United States
3 Germany
2 Spain
2 Poland
2 India
2 China
1 Switzerland
1 Portugal
1 Netherlands
1 Nepal
1 Korea
1 Italy
1 France
1 Australia
================
OxygenOS Official
19 Sweden
12 United States
10 India
9 Germany
7 Brazil
4 Canada
3 United Kingdom
3 Spain
3 Portugal
3 Malaysia
3 Greece
3 France
3 Belgium
2 Russian Federation
2 Romania
2 Netherlands
2 Mauritius
2 Italy
2 Israel
2 Finland
2 Argentina
1 Turkey
1 Singapore
1 Philippines
1 Panama
1 Pakistan
1 Norway
1 New Zealand
1 Latvia
1 Korea
1 Japan
1 Jamaica
1 Hong Kong
1 Czech Republic
1 China
1 Austria
1 Australia
================
OxygenOS Open Beta
19 United States
14 India
12 Sweden
8 United Kingdom
8 Italy
7 Spain
7 Romania
7 Germany
5 Poland
5 Canada
4 Turkey
4 Australia
3 Singapore
2 Russian Federation
2 Netherlands
2 Mexico
2 Greece
2 Finland
2 China
1 South Africa
1 Saudi Arabia
1 Philippines
1 Palestinian Territory
1 Norway
1 New Zealand
1 Malaysia
1 Luxembourg
1 Korea
1 Israel
1 Ireland
1 Iraq
1 Indonesia
1 Hungary
1 France
1 Ecuador
1 Denmark
1 Czech Republic
1 Cyprus
1 Brazil
1 Belgium
1 Bangladesh
================
Resurrection Remix-OS
8 India
6 United States
3 Canada
2 Turkey
2 France
1 Sweden
1 Italy
1 Brazil
================
Screwd Rom
1 United States
1 India
================
theOne5TOS
1 United States
1 Thailand
1 Saudi Arabia
1 Mexico
1 India
1 Brazil
================
Treskmod
2 United States
2 India
1 Germany
1 Canada
1 Australia
================
Validus
1 United States
================
xXx_NoLimits
3 India
1 United States
1 Romania
1 Netherlands
1 Indonesia
1 Germany
1 France
1 Bulgaria
================
Zoe ROM
2 Spain
1 United States
1 United Kingdom
1 Romania
1 Portugal
1 Poland
1 India
1 Greece
1 Czech Republic
1 Cape Verde
1 Canada
1 Austria
================

Firmwares by country

Argentina
2 OxygenOS Official
================
Armenia
1 LineageOS Official
================
Australia
4 OxygenOS Open Beta
1 Treskmod
1 OxygenOS Official
1 OmniRom
1 Liquid Remix
1 GZOSP Unofficial
1 crDroid
1 Codename Phoenix
1 Android Open Source Illusion Project
================
Austria
2 LineageOS Official
1 Zoe ROM
1 OxygenOS Official
1 Codename Phoenix
================
Bangladesh
1 OxygenOS Open Beta
================
Belgium
3 OxygenOS Official
2 Codename Phoenix
1 OxygenOS Open Beta
1 Liquid Remix
1 LineageOS Official
1 GZOSP Unofficial
1 crDroid
================
Bosnia and Herzegovina
1 Codename Phoenix
================
Brazil
7 OxygenOS Official
1 theOne5TOS
1 Resurrection Remix-OS
1 OxygenOS Open Beta
1 Codename Phoenix
1 Android Open Source Illusion Project
================
Bulgaria
1 xXx_NoLimits
1 Codename Phoenix
================
Canada
5 OxygenOS Open Beta
4 OxygenOS Official
3 Resurrection Remix-OS
3 Codename Phoenix
2 Dirty Unicorns
1 Zoe ROM
1 Treskmod
1 Liquid Remix
================
Cape Verde
1 Zoe ROM
================
China
2 OxygenOS Open Beta
2 OmniRom
1 OxygenOS Official
1 FrankenRom
================
Colombia
1 Hydrogen OS
================
Cyprus
1 OxygenOS Open Beta
================
Czech Republic
1 Zoe ROM
1 OxygenOS Open Beta
1 OxygenOS Official
================
Denmark
1 OxygenOS Open Beta
1 Hydrogen OS
1 crDroid
================
Ecuador
1 OxygenOS Open Beta
================
Finland
2 OxygenOS Open Beta
2 OxygenOS Official
2 LineageOS Official
1 Codename Phoenix
================
France
3 OxygenOS Official
3 Codename Phoenix
2 Resurrection Remix-OS
2 Liquid Remix
2 LineageOS Official
1 xXx_NoLimits
1 OxygenOS Open Beta
1 OmniRom
1 crDroid
1 Android Ice Cold Project
================
Germany
9 OxygenOS Official
7 OxygenOS Open Beta
6 LineageOS Official
3 OmniRom
2 FrankenRom
2 Dirty Unicorns
2 Codename Phoenix
1 xXx_NoLimits
1 Treskmod
1 crDroid
================
Greece
3 OxygenOS Official
2 OxygenOS Open Beta
1 Zoe ROM
================
Honduras
1 Liquid Remix
================
Hong Kong
1 OxygenOS Official
================
Hungary
1 OxygenOS Open Beta
================
India
14 OxygenOS Open Beta
10 OxygenOS Official
8 Resurrection Remix-OS
7 Codename Phoenix
3 xXx_NoLimits
3 Liquid Remix
3 LineageOS Official
3 Android Ice Cold Project
2 Treskmod
2 OmniRom
2 GZOSP Unofficial
2 FrankenRom
2 Dirty Unicorns
2 crDroid
1 Zoe ROM
1 theOne5TOS
1 Screwd Rom
1 MSM Xtended
1 Bootleggers
1 AOSP-Extended
1 AOSCP
1 Android Open Source Illusion Project
1 AEX Unofficial
================
Indonesia
2 Liquid Remix
1 xXx_NoLimits
1 OxygenOS Open Beta
1 LineageOS Official
1 FrankenRom
================
Iraq
1 OxygenOS Open Beta
================
Ireland
1 OxygenOS Open Beta
================
Israel
2 OxygenOS Official
1 OxygenOS Open Beta
1 FrankenRom
1 Dirty Unicorns
================
Italy
8 OxygenOS Open Beta
2 OxygenOS Official
1 Resurrection Remix-OS
1 OmniRom
1 Codename Phoenix
================
Jamaica
1 OxygenOS Official
================
Japan
1 OxygenOS Official
================
Kenya
1 Codename Phoenix
================
Korea
1 OxygenOS Open Beta
1 OxygenOS Official
1 OmniRom
1 Codename Phoenix
================
Kuwait
1 Audax Rom
================
Latvia
1 OxygenOS Official
================
Luxembourg
1 OxygenOS Open Beta
================
Malaysia
3 OxygenOS Official
1 OxygenOS Open Beta
================
Mauritius
2 OxygenOS Official
================
Mexico
2 OxygenOS Open Beta
1 theOne5TOS
1 Dirty Unicorns
================
Nepal
1 OmniRom
================
Netherlands
2 OxygenOS Open Beta
2 OxygenOS Official
1 xXx_NoLimits
1 OmniRom
1 LineageOS Official
1 Codename Phoenix
================
New Zealand
1 OxygenOS Open Beta
1 OxygenOS Official
================
Norway
1 OxygenOS Open Beta
1 OxygenOS Official
================
Pakistan
1 OxygenOS Official
================
Palestinian Territory
1 OxygenOS Open Beta
================
Panama
1 OxygenOS Official
================
Philippines
1 OxygenOS Open Beta
1 OxygenOS Official
================
Poland
5 OxygenOS Open Beta
2 OmniRom
1 Zoe ROM
1 Codename Phoenix
================
Portugal
3 OxygenOS Official
1 Zoe ROM
1 OmniRom
1 Codename Phoenix
================
Romania
7 OxygenOS Open Beta
2 OxygenOS Official
1 Zoe ROM
1 xXx_NoLimits
================
Russian Federation
2 OxygenOS Open Beta
2 OxygenOS Official
1 LineageOS Official
1 LineageOS kylothow
1 crDroid
================
Saudi Arabia
1 theOne5TOS
1 OxygenOS Open Beta
================
Singapore
3 OxygenOS Open Beta
1 OxygenOS Official
1 GZOSP Unofficial
1 FrankenRom
1 crDroid
================
South Africa
1 OxygenOS Open Beta
================
Spain
7 OxygenOS Open Beta
3 OxygenOS Official
3 Codename Phoenix
2 Zoe ROM
2 OmniRom
1 FrankenRom
================
Sweden
19 OxygenOS Official
12 OxygenOS Open Beta
2 MicroG LineageOS
2 LineageOS Official
2 Codename Phoenix
1 Resurrection Remix-OS
1 Dirty Unicorns
================
Switzerland
1 OmniRom
================
Thailand
1 theOne5TOS
1 crDroid
================
Tunisia
1 FrankenRom
================
Turkey
4 OxygenOS Open Beta
2 Resurrection Remix-OS
1 OxygenOS Official
1 Dirty Unicorns
1 crDroid
================
United Kingdom
8 OxygenOS Open Beta
3 OxygenOS Official
3 Codename Phoenix
1 Zoe ROM
1 Liquid Remix
1 Dirty Unicorns
1 AOSP-Extended
================
United States
19 OxygenOS Open Beta
12 OxygenOS Official
11 Liquid Remix
9 Codename Phoenix
6 Resurrection Remix-OS
6 LineageOS Official
6 FrankenRom
5 OmniRom
4 Dirty Unicorns
3 crDroid
2 Treskmod
2 Hydrogen OS
2 Bootleggers
2 Android Open Source Illusion Project
1 Zoe ROM
1 xXx_NoLimits
1 Validus
1 theOne5TOS
1 Screwd Rom
1 MoKee ROM Project Treble
1 AquariOS
1 AOSP-Extended
1 Android Ice Cold Project
================

I will update every week or so. Or when a certain amount of votes is exceeded.