MadMapper should work with any standard ArtNet or sACN compatible pixel driver.
You can have a look at garageCube hardware: https://shop.garagecube.com/
If you already own LED hardware and just want to replace Falcon for your NRTL issue, you can checkAdvatek Pixlite. We often use it. It has the advantage of not being limited to DMX FPS and has inter-device communication mechanism for precise synchronization.