Well, that mostly concerns if you want to mount your MyDocs to some windows-computer.
If you only use Linux, or if you never export your USB drives you can just format your mmcblk0p1 as ext4fs, it will work like that, no problems.

This has no effect to ubiboot, of course, excepting the fact that people normally put ubiboot configuration files in MyDocs/boot/ directory as that is the default location.
(but as well you could put them in mmcblk0p2:/boot/, it does not matter )