Which leads me to believe there's an issue with some code event listeners loading. Navigation tabs aren't working properly (not showing for XMG).
The template modifications problem is that template rebuilds complete unusually fast when triggered and aren't completing properly (add-ons not showing when/where they should).
I thought it was all related to XMG but Chris Deeming has helped me determine that there is some underlying issue here. I've upgraded to 1.3.5 and replaced all files with freshly downloaded ones. I've disabled and re-enabled add-ons one at a time. Nothing seems to help...
Thanks in advance for any insights you can provide!