Thanks very much, interested to see your thoughts especially with your work on Syscat! Since the last time we spoke I've added a fair bit more useful info to the documentation site, too, so hopefully that'll help.
Yeah I'm a big fan of using SQLite for it, and treating it as an ephemeral, point-in-time view, but I've spoken to a user whose company is taking it and shipping a subset of the data to Google Cloud's SQL offering, which is interesting and something I may need to look at as a "how would this work if it's long-lived"