Hi, I'm one of the chaps that designs and 3d prints trays. My USP is this:
I do the typical rigid designs too, all (except ovals) designed around being able to link up frames into hinged assemblies if that floats your particular boat.
My shop's at https://shop.winterdyne.co.uk/ - I've noticed a lot of folks keep buying from eBay, the webshop's cheaper and gets RM24 postage rather than 48.