So far, so good. My preference for an external input module is actually the Doepfer A-119, as it gives you a better choice of external connections. Another thing you should consider would be some modules to extend the capabilities of the sequencers, such as logic, clock modulators, divide/multipliers and so on. I wrote about this at https://uk.edubirdie.com/do-my-assignment.
These will let you create some rather complex interactions between the hardware sequencers you already have. You might also double down on some basic modules here, such as VCAs, EGs and LFOs to add some modulation complexity, plus the use of linear VCAs to control/change CV/mod signal levels as needed. Last, look at getting one or two Erica PICO MScales so you can easily translate back and forth between the M32 and DFAM CVs and everything else, keeping everyone in the proper scaling.
-- Lugia

I was going to buy Erica PICO MScales for my set. Thank you for advice.