Next time I'm at my brothers, i will try the independence exploit on his v10 (although he brought it second hand, and it has been opened at some point, so their is no guarantee that it has the right main board in it). If it works on a v9 & v10, then it must be the rare v11 that it don't work on.
AFAIK, there were 3 mainboards for the SCPH-50000 series: The GH-023, GH-026 and GH-029. I don't think that any of them had a different boot ROM from each other, but the DVD player ROM was updated for the GH-029.
If the Independence exploit still works on your unit, it'll most likely work on your brother's console as well.
The boot ROM is where the OSD and the "PS1 driver" is stored. So if that wasn't updated, I don't see why you will notice a difference.