I'm glad Mint seems to have moved off the plans to revive aptdaemon - that code has been on life support for a loooong time and is basically unmaintainable today (Ubuntu knows this and ports away from it, but phasing it out completely takes a while). I'd definitely welcome contributions to #PackageKit and its APT backend from Mint, which is actually actively used by new projects 😉 (and for dead certain could use and would welcome new contributions!)