Thank you DocH.I have the same head and tripod, with the same issue. Acratech makes a spacer that raises the head off of the platform to give it clearance. https://www.acratech.net/ballhead-riser-raises-your-ballhead-on-tripod-plateform/ Or, you could always have a machine shop mill you a plate of your desired height and diameter tapped 3/8" on the bottom and studded on top.
That’s one solution. It builds a bit much perhaps but I’ll look into it.
Getting a shop to produce a slim one would be an option as well. Didn’t think of that.
I’ve looked at some spare parts for Monopod top plates as well but did not find a suitable one.