[OnePlus 6T  ROMs, Kernels, Recoveries, & Other Dev] CoolApps:
This custom ROM works surprisingly well, I have to say.

Apps and launcher seem to be ready right away after boot, unlike with OxygenOS 11.

Got Magisk set up on it with SafetyNet reporting everything as being good.

Google Play is reporting the device as certified (although to be fair, it's appearing as a Pixel 6 Pro to the point where I got a 'welcome' Pixel 6 Pro email and a promo in Photos).

Widevine L3 is in use, as expected.

Camera is not so great, as I come to expect when it comes to custom ROMs. (Maybe there is a solution to taking full [or most] advantage of the camera again? Modified GCam even with the device specific config XML files still looks not so great compared to how it was before.)

Charging speed seems to be good (with the OEM charger and cable), as usual.

There are several things I had noticed in regards to issues:

1. It does look like the UDFPS is functional. Although I did notice that after booting up and unlocking the device, the sensor can still be unavailable until after a bit or entering the pin code again. After that, it works perfectly fine. So if anything, it's a slight minor inconvenience.

Not sure if relevant, but the logcat does show ANR and crashes of com.android.se (Secure Element Service) at first

There is a lot of "Invalid acquired message: 6, 0" and "Invalid acquired message: 6, 1" from "FingerprintManager"

At this point, it could be left as-is. Smoothing that out a little more is always welcome, of course.

2. When cutting or copying text, a toast shows up stating that "NfcService" had pasted from the clipboard. It can also happen without doing so.

3. When in landscape and then laying the phone flat (i.e. on a table or desk), the orientation suddenly changes to portrait.

4. I noticed that under developer options, the following options have everything in their radio list disabled except from "Use System Selection (Default)":

Bluetooth audio codec

Bluetooth audio sample rate

Bluetooth audio bits per sample

Bluetooth audio channel mode

This might kind of explain why Bluetooth audio is not functional.

5. When charging using the OEM charger and cable, for a moment it can show 'slow charging'. It would when quickly go to just 'charging'. Still charges fast, so not that big of a deal.

6. "Graphics driver preferences" under developer options appears to only have "default" as the listed option after accessing the listed "enable for all apps" option. Might be normal, but IIRC, OOS 11 at least had one more option.

7. Brightness goes to 0% by default when using adaptive brightness. This could just be that one thing that's not optimised out-of-the-box that will be sorted once you make the manual adjustments (so that it is 'taught'). So far after doing so, I had not experienced the issue again yet.

8. Sometimes when the brightness auto-adjusts by using adaptive brightness, the brightness change is sudden rather than fading to the new brightness.

9. Not sure if it is just me getting very used to 120Hz and 165Hz, but I noticed that scrolling doesn't appear to be that smooth in most cases. Compared to if transitions were to happen (which appear far smoother). Might be a bit noticeable while scrolling the settings main page or launcher app list.

10. This might be an Android 12 issue itself (as there have been issues with appearance on AOSP builds for many years that even made it to OEM builds [i.e. settings search layout -- issue appears to be resolved as of Android 12]). But if WiFi is on & connected to a network, the alert slider is set to silent (ensuring a crossed out bell icon shows up in the status bar), you are connected to a VPN and there is no SIM card inserted: when expanding the toggle part of the notification shade, the "No service" text would show way too close to the VPN (key) icon.

Some of the issues listed here are more crucial than others (some of which are more of notes).

The phone's no longer my daily driver. So I cannot test functionality involving RIL (mobile radio, calls, sms/mms, mobile data).