An incandescent on one lamp circuit shouldn't be affected by an LED on a different circuit. If an incandescent isn't working right there's an issue causing that problem to manifest.

If you want, I still have an assembled prototype of my LED adapters for the AUX board in Centaur. I'd be willing to send it your way if you want to give it a try. Basically does the resistor trick for you, right at the aux board, plug and play. And if it doesn't help, or you don't need it, it's completely non-permanent. Just yanks right back off.

-Hans