Hey skeller2023, welcome!
There hasn't been a lot of new development going on lately. The support is good though, there are number of really sharp users on here that are active.
I'm a casual user, I'm not 100% sure what you are asking with regards to limitations, so forgive me if I'm off base here. As long as you are using AdvancedHMI and adding to it (not taking parts of AHMI and adding them to other projects), then you can do whatever you want. Whatever you add to your project doesn't necessarily have to be GPL2. When it comes to deploying your project, you need to give the entire project to the end user to comply with the license. In other words, you can't just give them the compiled executable, you must give them the entire project.
https://www.advancedhmi.com/forum/index.php?topic=1092.0