I'm also very interested in both non-US sets, and adding raw coins, as well as adding other tpg slabs. I do see that the US sets still have definition gaps, just for even circulation/biz strikes, along with other set definitions, which I imagine may be filled in more before opening world coin floodgates, or for various paper notes/currency, etc.
Perhaps we can enlist volunteers to help assemble some various world coin sets.
Not sure, but perhaps a group dedicated to helping create various world coin definitions, where separate posts could be made for each country/denomination, and some people could probably request to help with specific years and strike types.
Small chat groups could be made with each denomination team of volunteers, too.
It would be cool to see multi-country sets eventually become viable, as well, along with other specialty sets.