Not sure if this is a bug or just something that should be called out explicitly in the user guide: The guide mentions that “The Note-Off layer activation will always use the velocity of the original note, regardless of any changes you make afterwards” and it seems that this restriction also applies to changes of pitch via Gxx, Uxx, and Dxx, though it is not mentioned.
This feels like a bug to me, but so does the velocity quirk 
Tested in 3.4.4 and 3.5.2 and it is present in both versions
Expected/desired behavior:
If I use something like a Gxx, Uxx, or Dxx command on a note then any note-off sample that gets triggered should have the pitch that the initial note ended on.
Actual behavior:
The note-off sample ignores the effects of the Gxx, Uxx, and Dxx commands and plays its sample at the pitch the note had when it was first triggered. The pitch of the note-off sample can subsequently be changed using fx commands, but it always starts with that initial pitch