Maybe this is what you have in mind, but I'd say this has to be accomplished in tandem with the other two PRs - that is, we don't want the package-template to lag behind the other two (admittedly, it already does... but that's what this is supposed to fix!)

Also, depending on how complex it is, we might want a short "migration guide" in the package-template that tells current affiliated packages how to switch to the new scheme.  That's not an immediate need, though - that can be done after all the rest of this.