Yes the limit of channels that Cuety can read in the fixture file is limited to 30,
Anyway the Cuety programmer can only display 19 different features/faders this is why we limited it to 30 channels max.
But, if your fixture is 40 channels and you create 2 custom fixtures of 20 channels, then you will be able to fully control your fixture. But some features will be on faders where the name doesn't fit.
The LPU works only with the Cuety app, Cuelux works only with the Cuelux cable or box.