Breaking news! As of today, the question "whether it would be possible" to debug the game running in Editor with Si3 has suddenly changed to "when it will be possible,,," This has happened after one of the promising techniques has shown to be standing on very strong grounds! The priorities to add Find All References and Rename Refactoring first remain the same, don't worry. I just had to investigate this a little further as I was recently inspired to do that after reading @lukaszunity's comments on Si3 and limitations of such solutions regarding debugging. The comments are here: http://blogs.unity3d.com/2015/10/22/monodevelop-roadmap/ Cheers!