Given you have a nerdseq I would get the more cv expander, while the envelopes are not as crazy as a zadar, you get lots of modulation capabilities integrated with the nerdseq ( love this sequencer), and a quad vca is a great choice veils is preferred by many but very hard to source. I would give this a go then see what you feel you are still lacking. I have heard mixed opinions on zadar. You really only need a buffered mult if you are looking for multing pitch cv but it doesn’t look like this is a focus or need in this case, you could use some attenuverters like a 3xmia, and I don’t see any random modulation source, marbles, wogglebug, divkid random step. The tough thing is you have a lot of big showcase modules and not a lot of room for modulation, that’s why I think the nerdseq expander would be a great choice over an ochd as you get 16 more slots for lfos and envelopes.