Not much in reality.
Proclethya has drive and saturation around the filter so anything after that will be affected sound-wise of course (envelopes, fx etc). I believe knifonium and Vacuum Pro both have the distortion around the oscs too so you’d get more variety of wave shapes gping into the filter too.
So I think you get greater control of your sound with VP or Knifonium, each voice effectively distorted/whatever as opposed to everything mushed together and distorted as one with post fx.
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