Pottery wheel bats - square drive instead of pins?

Hi all, my partner is the (novice) potter and we've just set up a proper studio space. She mentioned that she'd like some round bats for her wheel.

While looking into them it seems they usually attach with a pair of bolts through the wheel. i don't especially like that idea, for a few reasons - it seems fiddly, and like the holes would round out. It also means countersinking the holes in all of the bats to avoid an injury hazard.

I'm thinking of another approach, namely adding a square centre plate to the wheel (maybe 150mm square by 18mm high?) to engage in a square recess in the bottom of each bat. I could make an identical plate as an accessory for my router table, along with a template to cut the square holes in the bat substrate (eg 18mm ply). It would then be a simple job to produce perfectly round and centred bats of any size out of any material, simply by laminating a drive substrate (with the square hole) and a surface layer (without). I could turn them out in droves, any time I have some offcuts of suitable material.

Obviously having no experience with the pottery side of things I'd appreciate any thoughts or concerns the idea raises, suggestions of dimensions, or whether there's an existing 'standard' in this kind of thing?!