Yes I've thought a bit more about this topic and am actually writing up a response to my own post - Database are probably ok if you take a raw .sql backup; which is essentially plain text, or at least will be viewable in some form in the future.
https://sqlite.org/ "The SQLite file format is stable, cross-platform, and backwards compatible and the developers pledge to keep it that way through the year 2050." Doubt you can do better than that.