How can I tell if I'm using asmdefs everywhere I should?

My build time is 11 seconds long, but on a brand new project, it takes 5 seconds. I think this discrepancy is because I could be doing better with my asmdefs. Specifically, I'm wondering if I'm missing an asmdef somewhere that I should have one. How can I tell if this is the case? I'm looking for something more definitive than "use your eyes and make sure there's an asmdef in every root that has a .cs script." Is there someway that Unity can tell me if I did it right or wrong? Can it print out what it's compiling?