I just want to let you know that I've tried
asaf400's fork but none of the release APKs (signed or not) are installing successful.
Then I tried ko_hi's fork attached to the
first post and it installed OK. Here's a list of features that I came for and their status at my OP 7T @ OOS 12:
- Lockscreen tweaks
- PIN scramble

- Custom carrier text > Empty (space)

- Statusbar tweaks
- QuickSettings management > Tiles per row

- QuickSettings management > Tiles per header

- QuickSettings management > Haptic feedback

- QuickSettings management > Quick pulldown

- QuickSettings management > Memory usage bar

(there's a bar but without data)
- Battery settings > Battery indicator style > Circle with percentage
(at first there was percentage in circle, but icon was without a padding, now for some reason it doesn't work at all - shows always empty battery)
- Clock settings > Clock position > Right

- Progress bar

- Power tweaks
- Advanced reboot menu

- Display tweaks
- Unplug turns on screen > Disable

(also disables turning on screen when plugging)
- Navigation keys actions
- Home key > Long-press action > Got to sleep

- Back key > Long-press action > Kill foreground app

- Other settings > Lockscreen torch > On power long-press

(I had to allow GravityBox work in background in Android settings)
There are also "Quick unlock" and "Double-tap to sleep" in "Lockscreen tweaks" section that I always turn on, but in OxygenOS 12 they're already available in stock system, so GB is not necessary:
Most of the listed features doesn't work, but even so I'm really grateful for the work done, especially "Lockscreen torch" is essential for me
By the way I recommend you
SystemUI Tuner app, it's a nice add-on for GravityBox functionality, f.ex. for now I configured custom notification snooze times, disabled safe audio warning, disabled heads up notifications and set custom animation scales (0.3 in my case).