I had a fantastic week figuring out tech to make the 'manage tag siblings' dialog boot and work faster, even if you have hundreds of thousands of pairs. I now have a 98% working prototype that does everything--and a few workflow improvements--without needing to load up all the pairs on every boot. Rather than do a release tomorrow, I will copy this work to the manage parents dialog, polish the whole thing, and catch up on other work besides for next week.

v585 should be out on the 7th. Thanks everyone!