Exactly why "someone" ought to make a modulation module with plenty of features and outputs. Things like LFOs and envelopes would be useful.
If "someone" here means DSI, I don't see it happening. They focus on things that are sort of unique pieces of instruments that they've made, rather than on a complete synth. An LFO or EG would bore them to tears.
A preset system to store multiple configurations would be cool too. Of cause some extensions may be required to progress DSI style modulation features into something that integrates well with the eurorack way of doing things.
I think Intellijel pretty much nailed eurorack preset management with Tetrapad. You can save groups of voltages, switch between them with Pro-2-type strips, and even slew between configurations. If I ever expand my system, it will be for a Tetrapad.
Was also looking at a Doepfer Basic System A-100.
I used to have a pair of A-110 VCOs, and they're nice. Underrated, I think, if you want the saw core. Actually, every Doepfer module I've ever had has been solid as hell. And, hey, an A-100 system would let you support an Assimil8or.
And, to wrap back around to the actual topic of this thread... If you're interested in modular sampling, look into Morphagene, too. Dave Rossum is trying to bring the full computer-based sampler experience to eurorack, and the world needed that. But the Make Noise Morphagene (as does the earlier Phonogene, which I have) goes for an approach that can
only be done in a modular ecosystem. Every single thing that a -gene can do can be put under CV control, and that makes them a lot of fun. Phonogene is low-fi and full of surprises, while Morphagene is pristine, stereo, and allows computer-based editing via an SD card.
I'm struggling mightily on the question of whether I want to "upgrade" to a Morphagene. But I love the Phonogene so much that that's the only move I'm willing to consider with respect to sampling in eurorack.