Just a little by-the-way, we learned a trick on Qualcomm devices to get the device's region in fastboot.
We decided to include Global modemfirmware.img in our ROMs for devices that potentially have an eSIM and contain the modemfirmware partition.
The correct image will be flashed based on the detected device region.
Devices that will enjoy this change: Xiaomi 14 (houji), Xiaomi 15 (dada) and Xiaomi 15 Ultra (xuanyuan).
The other devices that potentially have an eSIM are not included in this change as they don't have a separate modemfirmware partition for the baseband, and instead have the baseband inside the main modem partition. The chance of incompatibility is high and we have no way of verifying that, so flashing modem.img separately will still be required (if you have a Global/India device).
How do you know if the change was applied in a ROM? If you see "modemfirmware_ww.img" inside the images folder.
("ww" stands for "worldwide", which is any region outside of mainland China).
P.S. I wanted to post this in Announcements, but the permissions are broken so I'm locked out of posting there for an unknown reason.