I now read the post and I don't believe.
I've got a MI4C where I installed the xiaomi.eu ROM 5.12.17 and I never did the update for fear the bootloader locked.
Now I read that xiaomi.eu does not block the bootloader. The updater offers me the update to version 6.6.5. I ask further confirmation; can I proceed? Nothing has changed since the last post?
If Yes, can I use the updater or TWRP? Thanks.