The Base3 supposedly won't work with DCS either.
Where was this stated?
Unless I missed something recently it "works with DCS" just as any Base would, and has in the past:
1.) DCS Remote controls TMCC/Legacy -- Connect the BASE-3 to your TIU, via a serial cable, and the DCS remote will operate your TMCC/Legacy locomotives through it.
2.) CAB-x App does not control PS2 or 3 -- The CAB-3 (App) and BASE-3 will not operate PS2 or 3 locomotives via DCS command, only conventionally using a PowerMaster, same as CAB-1/BASE-1, CAB-2/BASE-2, and CAB-1L/BASE-1L.