Does not work well with multiple pointers

[Kyuuhachi]

When having multiple pointers (e.g. via xinput create-master), moving either pointer causes both to become visible. This seems to be a limitation of XFixesHideCursor, so it's possible that it can't be fixed.

[Airblader]

As you already observed, I don't think this can be fixed either. Will leave it open for visibility, though.