When a ipapython.sysrestore.StateFile object is created, it reads its file into an internal state. Whenever that state is changed, it saves its state to the file again.
When several StateFile objects for the same file are used simultaneously, they do not know about each other's changes. The last one to save "wins", the other ones' changes are ignored.

We work around this by only using (even indirectly) only one at a time, but ensuring that requires rather deep knowledge of the installer internals, and it's one more thing to keep in mind when doing changes.
It would be better to automatically reuse an object for the same file if it exists.