I think I would do that (tallin->1u vca) - not sure how much space will be left in the 1u but nonlinear circuits do a 1u sloth in both intellijel and pulp logic formats - nice for slow modulation!
It's always a good idea to leave some space though - so I would get a blind panel to cover up the 6hp hole that's left
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities