I think UNT would be better off in the WAC. With the addition of Lamar (who has been at the FBS level before), that'd finally put UNT in a FBS Conference that has strong Texas flavor. UNT, UTSA, Tx State, and Lamar, would form a solid foundation to a Eastern WAC division, along with Louisiana Tech and New Mexico State. IMO, those peer institutions are a cut above the alphabet soup group you're in now with ULL, ArkSt, ULM, etc.
The coaching hires at UTSA and Tx State should tell you about their commitment to do this thing right.
Personally, I think you gentlemen should take a step back and consider the potential. Texas kids don't want to go to ULM or ULL. The new alternative of having a FBS alma mater in San Antonio and San Marcos trumps that. There is legit water cooler debate that can grow out of a WAC with that flavor.
Louisiana Tech also provides a nearby opponent that is just a cut above your current neighbors.
The only question beyond Lamar is how the composition of the Western WAC will shape up. I'm liking the addition of basketball-only schools like Denver and Seattle. Benson is going after major markets and he's leaving some good slack for future positive growth of a sound league.
If I were you, I'd be keeping a close eye on these developments. The WAC as a brand trumps the Belt. Their future locales can only help your cause if you have your sights set on the MWC.