Here is my personal fw+vendor path.
Flash the wanted zip before installing the ROM. Be sure about the ROM supporting of wanted fw version.
I try to keep it updated asap. I use miui dev as base.
https://drive.google.com/folderview?id=1CvhILBk1uDa6YdGr01xDt1m9W478xBl4
I'm on 9.1.10 (just got the 9.1.17 notification) is this the correct procedure: ?
- Format data -> yes
- Flash Havoc OS
- Flash gapps (nano)
- Reboot