You can try this franken-modem I made, no idea if it works, never tried this before.
https://drive.google.com/file/d/1qVqYwMqAAg5HzP-CeqEZtZFYPdkLudhv/view
And this here is precisely why we don't use any global modem.img in our ROMs. A perfect example.
Try images from other ROM variants like EEA, ID, TR, etc. Finding a compatible image is a matter of luck.
A lot of people have a grayed out Street View button in Google Maps, not just Xiaomi devices. Samsung, Sony, OnePlus.
Not sure why you ask a Google question on this forum. We don't know how Google apps work.
https://xiaomi.eu/community/threads/frequently-asked-questions.73215/
If you insist on touching the system apps in any way, don't report any issues here.
You can't do anything via fastboot with a locked bootloader.
This forum is not the official Xiaomi forum, try the official Xiaomi Community.
https://c.mi.com/global