grub-btrfs with timeshift didn’t helped me in my upgrade from fedora 38 to 39, when i rolled back with grub-btrfs, what loaded was weird mix of 38 and 39, that didn’t even let me browse my filesystem, got to disassemble laptop, get out ssd, use it as external, and even then half of the ssd was locked, ssd was new and chmod didn’t helped, even from live usb, had to copy files with testdisk and dd zero’s on whole disk for it to work again