This makes sense. I will add this to our backlog of features to consider for the next release.
After checking with support, it appears that as of VBAI 2015 f2 there's no ability to delete multiple VBAI state diagrams at once. I have an inspection with multiple states, and would like to modularize/strip off a small subset of the states to import to another inspection. I can delete one at a time, but would be useful to do this easily.