Once you've got Android12 stock flashed (I used UK one, as the OP Hong Kong one mentioned is in Chinese when it goes to download mode!) and TWRP (use this one:
https://xdaforums.com/t/android-11-recovery-a715f-twrp-3-5-1-ianmacd.4248487/ not the one mentioned by the OP, that didn't load properly for me), then flash Nekkoos ROM.
It's very good, I flashed the basic one (no Samsung apps) with Magisk and everything is fine.
It DOES come with Gapps. The camera app is the original with a few extras, so Macro is still there.
Maybe slightly faster and smoother. But none of that Samaung junk!
The audio is good, I use my phone as my only HD audio player and it's very good quality.
It's very Vanilla, so you'll have to install a lot of apps like Maps, Gmail, etc.
Well done OP, an excellent and the best ROM so far for A71!