I just provided a final patch for this. Now percentage and size should work fine also. Also custom child gauge positioning might have been buggy before. That should be fixed now also. Talon confirmed the correct functionality.
Edit: Oh yeah btw... I know I'm somehow considered to be the big asshole in this forum, but MAYBE someone might think about saying something like "thanks, appreciated" to people who provide code and bugfixes without being on the team and without really having the time for it instead of telling that person how much '****' he's providing.