I'm on 7.4.9, (rooted and with a factory cable to hand). The instructions for installing TWRP say to install "kfhd7-u-boot-prod-7.2.3" which I understand is the bootloader for OS 7.2.3 which is used because the later OS bootloaders were locked.
Now, if I flash that bootloader, and install TWRP, I can go on to flash a custom ROM. But if I just install TWRP for now, will the device still work with an 7.2.3 bootloader and the other images from 7.4.9 ? (or if I wish to continue with the stock ROM do I have to downgrade all images to 7.2.3?)
Also, are the checksums for the various stock images and files required to install TWRP around anywhere? Understandably, I'd like to verify them before starting.