@gadgetboy Sounds like you know enough and more technically than me:
A few random / side balls:
➡️ moving over outbox.json
➡️ Meow Viewer to view Mastodon offline and person here: @meowViewer
https://purr.neocities.org/ helps See your archive offline AND search it (nothing else does this - not even Mastodon can view it's own archive 🙄 )
Nothing like twitter where you could view it ALL offline at least as last resort - or if you know let me know!
➡️ boost all your posts from old to new
Just some ideas...