[Galaxy S6 / S6 Edge Unified Development] avidichard:
After a full day of flashing and reflashing. I have came to a conclusion on my side and a setup which works in a OK way. Could have more improvements but here is what I have for my Samsung Galaxy S6 SM-G920W8.

I have looked and downloaded many roms and as I saw in the thankyous and descriptions, most use LineageOS as their base for the custom rom. Basically, it's mostly LineageOS pimped up. So I resigned into re-installing this version following a user's suggestion and also realising that Magisk DOES help in downloading apps that are said to not be compatible with my firmware. So:

1. Boot with TWRP

2. Wipe and format data using TWRP

3. Copy LineageOS 16.0 ROM, OpenGApps Pico and Magisk v18.0 on internal storage (using Windows 10 on my side)

4. Install LineageOS 16.0 and OpenGApps right after before booting

5. Reboot WITHOUT Magisk

6. Configure your phone and account.

NOTE: System's initial setup application WILL crash and ask you to close once you arrive at the WiFi connection (well on my end it always crashes there). Once the initial setup screen is back from it's crash, go back using the back button and redo steps before WiFi connection setup, now, it should not crash.

EXTRA NOTE: A few steps after maybe the next, application MAY or WILL crash again, simply wait and go back like previously mentionned.

7. Once you have configured your phone at the initial setup, DO NOT open Google Play. Configure your settings at your will then, shutdown phone

8. Boot in TWRP and install Magisk

9. Reboot and have fun downloading and installing all your apps from Google Play which will work.

NOTES ON MY INSTALLATION:

First: Sorry if the terms are not exact as I use French on my cell phone.

- Added a sound and vibration when connection my phone to a power source. Phone rebooted without warning once I unplugged it. I disabled this setting for sound and vibration when plugged and unplugged from power source.

- I also disabled ALL animations. One hidden animation setup is in accessibility.

- I also enabled the programmer mode by tapping a few times on the version number in the system settings.

- In the programmer mode, I enabled ADB USB debbugging. A little lower, easily missed is how you want the cell phone to act in USB connection which I chose file sharing.

- I prefer to use Nova Launcher Free as it permits sooo many customisations and is the less buggy I've tried. I have gone over Evie and a few others and Nova Launcher has the simplest configuration with the most configurations available.

- 4K videos juste don't work or make the system pretty laggy (I had to try just by curiosity)

- I use VLC as video player

- I use MX Player as Music player because of it's ease of use for playing lists. But one could consider using only one as they both do the same job.

- I also use Microsoft Edge (ME) as my browser. Firefox is too slow, I just don't like Google Chrome and as a browser, surprisingly, ME is pretty fast and stable.

- I also activate in the programming settings the built-in terminal. No fluffy or overdosed apps, just the built-in terminal in LineageOS

- BIG DOWN NOTE: Messenger takes a while before taking a picture. The shutter sound is played BUT, you need to keep the camera steady until you see the send button. It took me while to understand that the camera in messenger is VERY slow.

- Boot time is, to my opinion, a tad slow but very bearable.

- BATTERY: The big one most people want to know. I have tried Oreo based custom roms and boy did I rush during the day to keep my battery just over 50%. With this version, I'd classify battery drainage is NORMAL. It's not excessively awesome, but compared to XtreStoLite I had before, I'd put them pretty much the same. Nothing to jump high about but at least I don't see a 2% off just by unplugging my phone from the power outlet like my previous rom. The battery life, to my opinion, is largely acceptable I ran 1080p videos in full screen for arround 5-15 minutes and I dropped from 98% to 95% which I think is very acceptable.

NOTE for battery: I have also enabled a few power saving mods like automatic lighting and disabled a few apps that have notifications enabled to my opinion, for nothing, for example, the calculator. I also use a DARK THEME built-in for all my apps including Microsoft Edge and MX Player.

- PHONE CALLS: I use GS Wave as I do not have a serviced cell-phone line, I use a VoIP service with voip.ms as my supplier. As for quality, did not change a thing for me. Calls are so-so, people have a little hard time hearing me depending on their provider and cell phone. Most landlines hear me OK. I pretty much hear them clear with some neglectable acceptions.

- Power button takes a small delay to turn screen on compared to other systems I tried.

- When a notification arrives, the 2 screen buttons (back button and show windows button) turn on and stay on.

- Dragging from top to bottom to show settings menu and notifications is a tad laggy

- Xposed is just not installable as the version for Oreo is still in Beta state, so forget any apps built on this

- I use AdAway for blocking inapp ads. AdBlock is already available in Microsoft Edge.

- Camera app offers up to 4K resolution but is also laggy for responding. The camera is, to my opinion one that should be improved as there are delaiys for capturing the pictures and even bigger delays in apps such as messenger as I mentionned above.

- GAMES: Work well but a bit slow to boot for some which were faster with XtreStoGen but one booted, works well without too much lag. This is not an S9, it's an S6 so I expect it to have some harder times in some apps.

- GPS: No comment, have not tried it yet.

- Blutooth phone call with GS Wave: Did not try it yet

Final NOTES: Do I like this? Yes and no! It's not perfect at all but we can't expect anything close to perfect on unofficial builds. I will be keeping this system as it does offer an acceptable working environnement. I'm a bit decieved to not see more Pie original builds that are not based off Lineage OS BUT seeing a very compatible build based on a maintained rom, I do believe that there will be many more updates to solve some issues. For now, my phone works like a charm and I am not too decieved to have taken some time in wandering how to solve my previous issues in my previous posts. I DO recommend this rom as all athers are mostly based off LineageOS so, heck with it, use the original and build on top of it.