I think there are valid points on both sides. There aren't very many 1A bands in the state that participate in UIL. Also, there would likely be issues with trying to fit another concert into the already tight schedule at TMEA. But I think there is more to it than the number of bands participating and the convention logistics. Shoot me an email. I have some other thoughts that might help with your proposal.
After doing a quick search of statewide marching band entries on texas music forms below is the number of bands entered in the region contest this fall. And this seems to be fairly consistent with fall 2018 and fall 2019. Fall 2020 was about half this total.
As far as how many 1A schools have bands, you might ask Dr. Kent, as I've spoken to him about this before. I believe there are around 30-35 1A bands that UIL is aware of, and maybe another 5-10 that don't go to UIL contest. Best of luck with your project!
I'm at a 1A school as a one-man show and truthfully, I don't believe the split needs to happen. There aren't enough of us to warrant it. I do believe in the 1A state marching, but that is a totally separate issue.
Marching band is what KEEPS us having a 1A band. Parents, admin, and school boards care nothing about funding a concert band, but give them something at football games AND send that "football" band to be recognized at state...? THAT keeps us in business.