Agree, this is a giant PITA. I think this could be easily fixed. The main sticking point with unix epoch is the SQLite CLI interface, but there could easily (?) be added some kind of mark to columns that it's an epoch timestamp and a client feature which parses those and formats the date. Done, problem solved.

Any code (usually one codebase) which looks at dates in a SQLite DB can already easily do these conversions, even at the application-level.