Recovering deleted Mac USB Flash Drive files, but on a PC

It's an interesting question, but I think I'm going to go with "no" on this one. PC file recovery programs are meant to recover files on a PC formatted volume, and likewise Mac file recovery programs are meant to recover files on a Mac formatted volume. I don't know of any file recovery program that has the ability to recover files on the "other" volume format. But even if there were such a program, the first thing you'd need is a way to read a Mac-formatted volume on a PC -- and the best solution to that is MacDrive which, yeah, requires a license. Without such a tool you'd be stuck; the PC can't recover data from a volume that it doesn't understand the structure of.