Alright I made the jump, though things dont yet work as intended. I flashed the latest lir-arm64-bvZ.img as per rayman's tutorial with xiaomi's fastbootd and vbmeta from the tuto (twrp's fastbootd does not register a usb-device on linux or windows for me.) the command succeeded. I then booted twrp 3.6 by nebrassy to flash the degoogled MinMicrog.zip by friendlyneibourhoodshane. Though it fails with "no free space on system", checking the mounted /system shows a partition size of 2.3GB with 1.6MB free space. Is there some dynamic partition magic I'm missing to reserve some space there?