ha, I thought this was about human voice.
yes, every rack should have lpg(s)! (ditch “never enough vcas”, this is no1 rule imo). I started with an optomix (as vca) and never regretted it.
the verbos harmonic oscillator is incredible, so is the verbos atc. I initially planned to use them together, but they both have/add so much color that using a clean vca (or none) after the HO and a grittier vco into the atc works best for me. both amazing voices.