Actually the T5 introduced a new balance slider, Keyboard (which changed R1, R2, R3 simultaneously) and the Genos removed this slider (then added the functionality back in via a later operating system update) and I suspect that's what you're dealing with. So make sure you G1 has the 2.13 os, then go into your faders and make one of the "Keyboard" and then when you're changing registration settings. The Genos 2 added this fader back in due to this!
Midi files on arrangers *can* contain a snapshot of the settings at that moment, so yes, midi files created on the T5 could also later your "keyboard" fader.
Mark