Hey fryedrycestyle,
I’m going to start looking into this, but you’re using an awfully old version of engine at this point, and anything I find will likely already be fixed in a newer version. Have you attempted using 4.6.1? 4.7.0 should be out soon as well, so you can look into 4.7 Preview 8 if you’re interested. Both of those should run substantially better and have many fewer issues than 4.2.1 when running on Yosemite (10.10).