@Lugia Sounds like utilities/modulations sources are the way to go with the limited space I have. When I first saw you recommended After Later DVCA I was a bit surprised as I already have the Quad VCA. But just last night I noticed I was using all 4 VCAs and now see how the additional 2 on the DVCA would be useful.
...thereby demonstrating the modular synth truism that "You can never have too many VCAs".
re: the 4ms Listen I/O, this looks useful but I probably will not use the input as the only thing I really use my rack with is the sq-1 or a Neutron. But I like the output as I use headphones so I'm considering the PICO output as it is only 3hp and has the output which I could use if I ever decide to record anything. Right now I'm just using a cheap headphone attenuator plugged into my VCA with my headphones.
-- sndbyte
Another consideration would be Happy Nerding's new version of their Isolator. 4 hp, balanced 1/4" outs plus a headphone preamp, a stereo ganged master pot, and transformers. I mentioned this elsewhere today, but the upshot there is that transformers do plenty of stuff...they block DC from getting into your monitoring chain (which you REALLY don't want!), they keep induced crud and ground loops under control, and just like other transformers, you can hit them harder and you get this nice, euphonious saturation that can punch up sounds (especially in the lower octaves). Wins all around.