Channel Plus 2100A IR Wall Plate Insert w/RF Out

I have this setup with a CP 550BID amp, a 5415 mod (which provides the power for all), an IR receiver and an emitter, and it they all work nicely for whole house distribution of CATV plus modulated signal. Some tricky issues (all documented, but easy to miss): (1) if you connect TVs to the 550 without a 2100a you must use a DC block, (2) if you use any standard splitter (not IR splitters) the IR DC signal will not pass through