[Huawei Mate 9 Questions & Answers] Leighm0:
In an interesting attempt to see if VoLTE was running on my device (but simply not showing the options), I ran the "Take bug report" (Full report) in Developer options and emailed it to myself. I downloaded the ZIP file it emailed me and extracted the contents... Some interesting details were found in the "bugreport-HUAWEILON-L29-2017-03-21-13-37-04.txt" file.. I searched its contents for "volte" and found these entries...

Here are snippets taken from the file:

[persist.dbg.volte_avail_ovr]: [1]

[ro.config.hw_change_volte_icon]: [true]

[ro.config.hw_volte_dyn]: [true]
[ro.config.hw_volte_icon_rule]: [2]
[ro.config.hw_volte_on]: [true]

settings/system/hw_volte_user_switch: pid=18162 uid=10004 user=0 target=fc486ae

system icons: 11
[0] icon=StatusBarIconView(slot=data_saver icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f02066f) user=0 ) notification=null)
[1] icon=StatusBarIconView(slot=hotspot icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f020696) user=0 ) notification=null)
[2] icon=StatusBarIconView(slot=managed_profile icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f02069a) user=0 ) notification=null)
[3] icon=StatusBarIconView(slot=cast icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f020611) user=0 ) notification=null)
[4] icon=StatusBarIconView(slot=bluetooth icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f02062e) visible user=0 ) notification=null)
[5] icon=StatusBarIconView(slot=tty icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f020732) user=0 ) notification=null)
[6] icon=StatusBarIconView(slot=zen icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f020746) user=0 ) notification=null)
[7] icon=StatusBarIconView(slot=volume icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f0206a2) visible user=0 ) notification=null)
[8] icon=StatusBarIconView(slot=alarm_clock icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f0205e6) visible user=0 ) notification=null)
[9] icon=StatusBarIconView(slot=volte_call icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f0205c5) user=0 ) notification=null)
[10] icon=StatusBarIconView(slot=eyes_protect icon=StatusBarIcon(icon=Icon(typ=RESOURCE pkg=com.android.systemui id=0x7f020310) user=0 ) notification=null)

++++++++++++++++++++++++++++++++
ImsPhoneCallTracker extends:
CallTracker:
mPendingOperations=0
mNeedsPoll=false
mLastRelevantPoll=null
mVoiceCallEndedRegistrants=android.os.RegistrantList@6d75f4b
mVoiceCallStartedRegistrants=android.os.RegistrantList@7be9d28
mRingingCall=[ImsPhoneCall RG state: IDLE ]
mForegroundCall=[ImsPhoneCall FG state: IDLE ]
mBackgroundCall=[ImsPhoneCall BG state: IDLE ]
mHandoverCall=[ImsPhoneCall HO state: IDLE ]
mPendingMO=null
mPhone=Handler (com.android.internal.telephony.imsphone.ImsPhone) {18148d4}
mDesiredMute=false
mState=IDLE
VoLTE: enabled
ViLTE: enabled
VoWiFi: disabled
ViWiFi: disabled
UTLTE: disabled
UTWiFi: disabled
++++++++++++++++++++++++++++++++
ImsManager:
mPhoneId = 0
mConfigUpdated = true
mImsService = com.huawei.ims.ImsService$1@4fb4a41
isGbaValid = true
isImsTurnOffAllowed = true
isNonTtyOrTtyOnVolteEnabled = true
isVolteEnabledByPlatform = true
isVolteProvisionedOnDevice = true
isEnhanced4gLteModeSettingEnabledByUser = true
isVtEnabledByPlatform = false
isVtEnabledByUser = true
isWfcEnabledByPlatform = false
isWfcEnabledByUser = false
getWfcMode = 2
isWfcRoamingEnabledByUser = false
++++++++++++++++++++++++++++++++

PROVIDER ContentProviderRecord{4b2bb61 u0 euid:0 com.android.providers.settings/.SettingsProvider} pid=1011
Client:
GLOBAL SETTINGS (user 0)
_id:239 name:mobile_data0 value:1
_id:240 name:mobile_data1 value:1
_id:36 name:low_battery_sound_timeout value:0
_id:27 name:car_undock_sound value:/system/media/audio/ui/Undock.ogg
_id:42 name:convert_brightnesss_factor value:3.2
_id:40 name:volte_vt_enabled value:1
***more items inbetween***
_id:62 name:hw_volte_user_switch value:1

Now I don't exactly know much about this, but if what I am reading is correct, VoLTE is enabled on my device....

Edit: I however have tested making calls, soon as I make a call the 4G+ signal icon changes instantly to 3G or H+ ... So my guess is the VoLTE doesnt work, so it downgrades it to 3G/H+ call... so I guess I need to try and get the Australian/Telstra VOLTE files from somewhere for this device :(