The main reason I never got around to implementing archive support in Mangariini is because I never saw the point. Why would you want to obsessively keep all your comics in archives? Why not just unpack them once and have it over with, and then you can use the files for anything without having to seek out special software?
This isn't the eighties any longer. I can have thousands of files in directories, and my computer won't break a sweat. I really don't see your point.