Yo, Xiaomi recently swapped my Vayu's motherboard after it bricked; I was using it for a bit over a year and the last months it would shut off and get stuck on the POCO logo but then it works. A month ago, I decided to unlock the bootloader and install a custom ROM and the issue got a lot worse. Finally it bricked after trying for the 100th time to miflash stock ROM lol. But yeah, fast forward today, they replaced the motherboard and I immediately unlocked the bootloader and flashed Arrow OS and it works perfectly. I don't think unlocking the bootloader accelerates this issue, but if you have been using the phone for a year or so, don't unlock it I guess and try not to turn it off lol...