+1 on bigger cab. Especially if you're insisting on using big honkers like that Verbos Harmonic Oscillator! Otherwise, you're going to have a problem with a single VCO that takes up 32 hp of an 84 hp row.
Or, consider this: are you really looking for a Eurorack solution here? If you dig the sound of that oscillator, fact is, you might ACTUALLY be happier spending the extra money for a small(ish) Buchla system. Yeah, it can get VERY spendy, but if the West Coast methods are really speaking to you, you might as well consider tossing that cash at a long-term solution of THAT sort. This build is up around $2500 already (modules + case) and it's only 2/3rds full. By the time you fill those spaces, you're actually heading into the zone where another few hundred bucks (if that!) can get you a Sound Easel. No lie...see here: https://buchla.com/systems/ And honestly, that sort of move would make LOADS of sense, as the Sound Easel is one of those "best teaching synths" (along with the ARP 2600) and you can learn tons from following how Don intended things to work.