output a configurable universe (E1.31 or ArtNet) via MAX485 module that connects its DI to D4 on d1_mini.
as this function competes with DMX output for the same hardware, the universe to proxy acts as a switch.
0 = DMX OUTPUT (of configured WLED LEDs, which is the classic behaviour)
1-63999 = DMX PROXY (selected universe, ArtNet is limited up to 32768)