Awesome, this is great to hear!
Despite that, I went ahead and installed a brand new graphics card. When I originally posted this thread, I was running on the very low end of the spectrum with an Nvidia GTX 550 Ti. While I’m still on the low end, I upgraded to a GTX 750 Ti tonite and I am pleased to report that the editor lag is basically a non-issue now. Building paths no longer hangs at low percentages, and instead completes quickly, as would be expected.
Once fully built, with full realtime graphics and nav visualization on, the in-editor frame rate is still not perfect… but it’s definitely smooth enough to continue development. Guess I can consider this solved on my end! Thanks for the input, ddvlost!