I've been using Wifi based mixers for years, if you have a real router, you won't have any problems of drop out, the Behringer series with the built-in routers seem to only work at home, and with maybe 25 feet of reliable range. They are great mixers, sound great, but you need an external router.

Since then I have used many different ones, I've settled on the Yamaha TF-Rack, for a lot of reasons, but for especially one, is that at any time I can do anything right on the touch screen if I need.