I have super thick MOP buttons on most of my Borrelli shirts, and I love them.
They look fabulous, and I'd think that they are more robust against dry cleaners.
The buttonholes can be made larger to accomodate the thicker buttons. I don't think that's a problem.
Therefore, I vote for super thick buttons, but if I'm alone with this, then of course any high quality, white MOP button (not thinner than the current 'thick' version) will do. Any suggestions for suppliers?