Yes, I didn't consider module depth for a specific case. It looks like a 4MS Pod20 can support modules up to 34mm deep.
I figured that anything in the rack you posted was fair game for this hypothetical 20HP system.
20HP is a very significant restraint... are you planning on using this small case with others at some point? I personally understand and appreciate the attractiveness of small cases for focusing on and learning specific modules, but 20HP feels much too small as a standalone unit. Do you already own a case or any of these modules? Or are you in the beginning stages of planning out a system? If you are just getting into eurorack, I would recommend getting a larger single case, rather than several miniature ones. This is advice that you will hear quite frequently on these forums.
-- Chace
first 20hp standalone and later with other hp ascending pods, because the restraint random chaotic is ok, i was thinking delta-v, bongo cv and athru