Both the Poly and the FH can do the job. The FH simply allows you to configure everything. The Poly automatically does everything. You’ll notice that the poly has only 4 cv’s per voice. This means that velocity is combining velocity on and off into one and you don’t really know specifically what modulation is capturing. Whereas on the FH I can configure all 5 parameters of the Roli to individual jacks. You can do more than that though, as you can configure exactly which CCs to listen to and route.
The master plan is to let go of the Poly, and replace it with some other analog goodness. I can do this because the FH-2 can be a host and client at the same time, and you can configure the ports to respond accordingly. So like the first 20 jacks for the host mode device, and the remaining 12-44 (You can have up to 64 jacks using the FHX-1 extender modules) jacks to the client device, as one example.
If I could ever get a Rabid Elephant module I’d already have the Poly out.
In the above picture the Toolbox is sending midi to it via the midi out. So it is controlling the 4 Doepfer A-111-3s with CV and Gate, and is duplicating that across the midi out for the Poly which is controlling the 4 Tiptop Audio Z3000s.
There are many options out there, but I’ve just found the FH series to be the most configurable.