For what purpose? The only way that can possibly work is if the particular VSTi you're using can be configured as an audio effect and then it has to be placed in the effects rack of an audio track.
I spend most of my time with Labs making music, not staring at the installer. I don't really care what the app thinks. They are on my computer and they make noise anyway.
Its kind of a known bug in the Spitfire app that doesn't affect whether the libraries work or not.
I'm with you on this. I got my old Korg X3, a Minilogue and more VSTis than I will ever use. Along with a bunch of guitars, two basses, a bouzouki and a drum kit. I'm working on making the most of what I have and weeding out what I never use.