Yes, making a fork from the newest version that allows it would be the way to go. I am quite unfamiliat with PS1 emulation but perhaps there are others anyway?
Open source freedom means that the author can have crazy license, and we can just not use it or look for alternatives
I usually just check out another copy in another directory, say I am working on Foo.
foo/
is the dev playground andclean-foo/
for a clean checkout from master.I know you can do it all with commands but I just find it easier to diff between directories or check how things are in master without touching the dev dir.