The functionality to set up or test a blueprint by clicking on the setup or run test buttons while holding the blueprint to be tested in your cursor's hand does not seem to be working in 2.0. (Note: I never used this mod in 1.1, so I'm just assuming it's the 2.0 update that broke it rather than it having never worked.)

are you trying to place a blueprint that is in your inventory, or one that is in blueprint storage
I ask because blueprints from blueprint storage for some reason are not marked as blueprints and so they will not work until i work out how to tell them apart from random items in the hand

From storage. The whole point of using one in my hand was so that I [i]didn't[/i] have to remove it from the blueprint library. Moving them into inventory means that they aren't available in my actual game, where I need to use them; worse, if I close the tester world without saving, the blueprint is gone forever. (I lost a couple blueprints that way doing it via the place-in-box method; fortunately I still had the lab world where I had created them, so I was able to recreate the blueprints with only moderate trouble.)

this is fixed in 0.9.5, though the BP name will show as "BP from library" as blueprints in the library are stored oddly and I haven't yet works out how to extract the name

Doesn't seem to be working. Clicking on the button while holding a library BP does nothing in 0.9.5.