Polishing clear epoxies like HXTAL

I have a couple of intarsia pieces I’m trying to polish, which have
areas which have been filled with HXTAL, which is a super clear,
museum grade 2 part epoxy. It works great, but ridiculously hard to
get the scratches out when polishing, especially the flat parts. It
seems nearly impossible to get a completely clean finish. i mean, it
polishes up fine, but i can still see the scratches. Rounding the
surface helps, but not always possible. Does anyone have any tricks
for this?

Possibly zam.