Fastest way to reload managed DLLs?

Long iteration times were driving me nuts, especially "Reloading Assemblies", so I moved much of my code outside of the Unity project, into a separate solution which compiles to DLLs.

The fastest way I found Unity to respect changes to my DLLs is domain reloading but it would be nice if there was an even faster way to do this. It seems unnecessary having to reload so many things unrelated to my changes.

Please let me know if you have any ideas!