Packfile format, TT #451, and supported releases

[Patrick R. Michaud]

TT #451 says that the packfile structure is 'experimental'.
Does that mean that the packfile format is unstable -- i.e.,
it doesn't follow the deprecation policy?

More to the point, if a compiler is writing its own packfiles
instead of using imcc to do it, is the code that generates the
packfile guaranteed to work across supported releases?

Or does IMCC remain Parrot's only supported interface for generating
bytecode?

Pm