I went a couple of steps further with this remix of a remix of this original part.  I loved and kept the recess for the backplate.  It's perfect and was just genius.  I pretty much kept the overall design as there was no reason to change it.  so what did I change?  I added countersinks to the surface holes as I found that socket head bolts were not usable due to a rubbing issue with the top bezel, and button heads still rubbed a little too.  M5 Set/grub screws would have worked well but I found those a little difficult to find.  The other option was to use the original pins, which meant a deconstruction that those without the tools to do it, would not have on hand.  So I did the countersinks and used countersink M5 bolts.  I also tightened up the inside hole to give the threads a bit more to bite into so the wouldn't walk out over time with the vibrations.  It did make a difference in feel. so far over the last few weeks of testing, they haven't budged, so I think it's good.  Let me know if this works for you.  Print two and just flip one.. just like the OEM replacement part.  And if you print this with ABS using 60% infill cubic(what I used and VORON specs out 40% for those printed parts), it's still almost half the weight of the original XY blocks, so added bonus there.  Prints now look better on the X and Y surfaces overall.  The belt ripples are gone for sure.
These parts are going to be responsible for your motion system so they need to be durable and light
I'd use ABS/ASA/PC/Nylon (any high temp engineering grade filament.  I do not recommend PLA or PETG
40%-60% infill
supports will help where the overhang for the belt path is.  I used the standard snug infill with .15 spacing on Z top and bottom to make it cleaner to remove.  It's not smooth, but who cares?  It's all hidden by the back plate and the little bit of extra interface material provides more friction for the bearing so they do not slip out during run time.

My bock next to original Elegoo block for comparison in photos