Blocks could be more eager about closing popup warnings and mutators

One of the more annoying experiences in the blocks UI is making a bunch of changes (say, removing extra constructor fields), then realizing you have to go back and close all of those mutator windows. I think it might be easier if they closed on their own. For example:
1. If you open a second mutator, shouldn't the first one close?
2. If you click outside a mutator, should it close?

I'm not sure I know the answers here, but I suspect the way it works now is not optimal.