As I prepare to do this, I have a question.
On mastodon, there’s a self-destruct command for a clean exit to avoid problems from server keys being remembered, that is recommended not only if you are closing down a server, but also if you are resetting an instance to the point where you are regenerating new keys. I don’t know whether you have run into this in your testing so far. It looks like Mastodon does a Delete Actor for each local Actor. I don’t see functionality to do this in the plugin, but I recognize that I might be missing it.
For the mastodon server I run, I think that tootctl domains purge should be enough, but I’ve also been testing with a vanilla mastodon “alt” where I don’t have admin. 
…I did the restore, and as it happens, event tootctl domains purge isn’t enough for me to be able to successfully follow after the restore. The posts just don’t show up on Mastodon at all. I have enabled verbose ActivityPub logs so that I can debug more, but I haven’t found where to look to find them. and I have now found them in the rails logs, so I should be back to being able to investigate on my own.