This makes sense.It's fascinating how many ways there are to do something.... just how much work people will gamble against how much risk they are willing to take.
Chaining it to a tree and driving forward will probably accomplish something, but you don't have any control over what that might be. It might even be the PTO Housing or even the rear end casting that comes loose..
I would try that idea with the ratchet strap first. It's pretty safe. It appeals to my own bias towards solving problems with more work and less risk to expensive parts.
If that didn't work, my next move would be even more conservative. I'd take the PTO shaft apart until it was possible to put a standard gear puller onto the coupllng. That might involve some hacksawing and a new PTO shaft, but it insures that pulling the coupling off won't do any farther damage to the PTO. And there is zero chance of damaging the PTO housing
rScotty
The chain and drive forward method sounds like something I would do, after getting frustrated and when I should be walking away from it for a while.