Investiate FIP-0074 Cleanup

[BigLep]

Per discussion in https://filecoinproject.slack.com/archives/CP50PPW2X/p1726838346989029 , there is some reason to believe that certain state related to FIP-0074 isn't being cleaned up as expected. This is a tracking issue to do this investigation to determine whether there is a bug or whether things are working as expected.

During 2024-10-02 maintainer conversation, this wasn't deemed to be urgent. It's being left here as a good "trial by fire" ramp-up task for newcomers to the codebase.