The upgrade to a pro is already there, just not enabled without the proper license.
Bed or working area size is limited by the lens length. I have an F420mm that covers about 300mm square. There exists what’s referred to as a flying galvo head, where the galvo is on a gantry and can move.
Coins take an hour or more to do, are you patient enough? Unfortunately you can’t really tell what it’s going to be until it’s done.
Doubt you’ll find it easy to do multiple coins, but I’ve never tried it myself. They have to have perfect alignment or you eye can see it.
