Hey ronnz98,
the Mi 9 (cepheus) has been well maintained for years (from Android 10) until today iodéOS 4.9 (Android 13) by iodé.tech chief developer @vince31fr. Official ‘stable’ iodéOS is like /e/OS based on LineageOS.
[ROM][cepheus][A13] iodéOS = LineageOS 20 + MicroG + adblocker
device tree cepheus
kernel cepheus
Don’t you want to build a new /e/OS-T v1.19.1 ROM?
PS: Member @petefoth has been building iodéOS ROMs for Sony devices for a while.