The transaction behavior is fine, it's more that I've had people delete function declarations from scripts while never cleaning them up in the data warehouse and then you end up with old functions kicking around in prod. My use case is mostly warehousing, not application stuff, so I don't care about full blown migrations. Just "these are the functions that we have declared for use, no more no less".

It seems like with DBT we're getting to declarative table construction, but I'm looking forward to declarative maintenance of other data warehouse aspects.