When you're using update.txt, ldr.bin is working. But it's not implemented in bootloader.
When you're flashing RGN file, things are more complicated.
When the device is in pre-boot mode, bootloader is working initially.
But then you can flash RGN file with boot.bin, and boot.bin will be executed, and receive/flash the rest of the regions.
If you flash RGN file without boot.bin, bootloader will receive/flash the rest of the regions.
Bootloader and boot.bin have a number of regions not writable over USB (software limitation, including region 41).
Boot.bin has a number of regions not writable over update.txt (software limitation, usually not including region 41).
In your particular case boot.bin can't write regions at all (over USB and by update.txt), but bootloader can write regions.
I think this is caused by the difference in the flashing algorithms and partially broken hardware.
I will try doing it on the following weekend, okay?
Hi any chance you make that payload to erase corrupt rgn 41? I still have hope to jump start my 265w
I do remember about you. I will tell you when I have something.