Well, in the current upgrade-in-progress the plan is to modify the code-generator in such a way that regions marked by the user are preserved, so it has to generate to a textbuffer in-memory anyway, so checking what's changed isn't that bad. However what can't be avoided is that if the time is written into a file, it still looks as if it's changed. So the only option there is to remove teh time from the template header.
This can only be done if there is some sort of log being created which files were changed during the generation process, as it is otherwise impossible to track down when a file was generated (and I really would like to keep that option). I don't like a separate log though, as it can get lost/overwritten and the information is gone.
I'll think of something.