TWRP 3.4.0-0 for Xiaomi Mi 9 (cepheus) by mauronofrio:
Main changelog: https://twrp.me/site/update/2020/06/24/twrp-3.4.0-0-released.html

Install via magisk
TWRP 3.4.0-1
TWRP 3.4.0-1 Mod Theme

Install via twrp

Change the watermarks for Miui 12

Change The Model

MIUI Auto Brightness Fix V1.1

Works on MIUI based roms (Android 10 only).

New Immensity Auto Kernel build by @utsavthecunt (28.6.20)

Notes:
- FOD works on MIUI12
- for FOD to work with MIUI12
edit /system/build.prop and set ro.fod.dimlayer.enable=false
- MIUI is still not officially supported keep that in mind and do not report bugs
- For Cepheus, uses OSS FOD version

Changelog:
https://raw.githubusercontent.com/UtsavBalar1231/updater/master/changelog

Download:
https://sourceforge.net/projects/unofficialbuilds/files/raphael/kernel/iMMENSITY-AUTO-SM8150-OSSFOD-28.06.2020.zip/download

For more details join our community discussion! @UOCepheus

Changelog for AOSP:

- Upstreamed to LTS: 4.14.186
- Upstreamed Low Memory Killer by Sultan Alsawaf @kerneltoast
- FOD Improvments (Use qcom drm notifier for event blanks)
- disp: msm: sde: prevent CPU from sleeping while processing display IRQ
- soc: qcom: smp2p: keeping inbound entry on freeze
- ARM64: dts: sm8150-common: Disable all PCIe and MHI nodes
- cpufreq: Only block min freq setting for booster processes
- qos: Don't allow userspace to impose restrictions on CPU idle levels

NOTE: Kernel version remains on r16 because I forgot to change it

NOTE: Userspace is the plain where roms and user can tamper in kernel settings by a good or bad way

Download here: https://github.com/Official-Ayrton990/Quantic-Kernel-AOSP-Cepheus/releases/tag/r17

Changelog for MIUI

- Initial Release
- Upstreamed to LTS: 4.14.186
- Upstreamed to CAF: LA.UM.8.1.r1-15100-sm8150.0
- FOD Fixed by @sekaiacg
- FOD Improvments by @Laulan56
- AOD and FOD on AOD Fixed by @Ayrton990
- GPU Overclock to 835MHz
- Fsync toggle and Dynamic fsync
- Disabled all qcom boost
- Use qcom drm notifier on all fingerprint and touch drivers and objects
- PELT Scheduler
- Scheduler backports for general performance and baterry consumption

BUGS: Anti screen flickering not working and dont try to enable or your would never be able to boot the rom

BUGS: Since I'm using magisk to solve some issues of FP coming from M.O.D Kernel or Evira Kernel will bootloop your device, be aware.

Download here: https://github.com/Official-Ayrton990/Quantic-Kernel-AOSP-Cepheus/releases/tag/r17-MIUI

New builds out!
-Upsteam 4.14.187
-Maybe fix up the bugs of double weaker?
-Support the screen oc
-Removed unused reserved memory

Sorry I didn't fix the AOD because I must prepare for a very important test.It's very important to me and my future.

Skyhawk Recovery Project | New Build
📱Device name – Xiaomi Mi9
🤖Code name – cepheus
🦅Shrp version - 2.3.1
👨Maintainer - @Giovix92

Status bar two lines version V12.0.2.0 Eu

Status bar two lines version V20.7.9 Eu

Note: have not been checked

Status bar two lines version Masik X 15.0

Note: have not been checked

Version 4.2:
- Updated CPU Optimization
- Updated I/O Optiomization
- There are four custom profiles: Power Save, Balanced, Performance, High Performance
- Add GMS Doze

Note: Works well on kernel stock.