Pickling Patch can be useful in multiprocessing, you can pass the Patch argument to function executed in other process. It can also be useful if you save the state of your program and restore it at the next start. In both cases you pickle and unpickle on the same computer.

If unpickle Path on other platform, the only meaningful operation on result are these which are implemented in PurePath. So Antony's proposition looks reasonable to me.