Just clarifying, you're talking about 4.4mm's 5-points of contact vs 2.5mm's 4 points of contact? If you're talking about the number of contacts, well I'm sure
@CraftyClown's balanced cable has only 4 groups of wires (L+, L-, R+, R-) running through it (i.e. no 5th ground/earth wire in the cable). So the 5th point won't be used anyway.
OTOH, if you're talking about size of surface area, I don't believe the socket would be leveraging on the available surface area as the contact points are literally springy points of contact rather than surface-area-of-contact in which case direct 4.4mm vs 2.5mm (or 3.5mm) -> 4.4mm isn't going to improve sonics. If anything, the type of coating (gold plated, vs rhodium, etc.) is probably going to matter more. This is my opinion only - w.r.t sonics. Someone do feel free to correct if my understanding is wrong.
As such, my recommendations to him was more on practical flexibility of (re)use of the cable for other DAPs/Amps.
P.S. Side note, I'm asking Hiroaki-san if the ground of the 4.4mm is implemented on the 1Z or not. I can see the ground being implemented in their desktop TA-ZH1ES but grounding onto mobile/portable chassis?