The app doesn't expire; you just have a limit on how many "pinned" domains or active "Map Local" rules you can have at once. The Professional Advantage (Buying vs. Cracking)

Improperly modified binaries often cause memory leaks or kernel panics on macOS. Is There a Permanent Way to Use Proxyman for Free?

The term "patched" in this context usually refers to two things:

The good news is that you don't actually need a crack to use Proxyman. The developers offer a very generous that is not a "trial"—it lasts forever. What you get in the Official Free Version: