I dont use that twrp anymore. Im using the New Version from mauronofrio
This twrp is closed source and i dont know what they Do under the hood thats why i use another.
Are you rooted? And You can try to go into Dev Options. Set Advanced Reboot Menu on. With that You can Direct Boot into twrp from the Rom without Key Combo
He menans the macro Mode in camera. This Feature is in the Stable builds from mi9 but as You said u dont Release old firmwares and thats okay. In the weekly builds all Features are available