I have never had any issues with air bubbles in my front brakes when replacing the lines, going to dual. My K6 has the stock brake switch.
My Goodridge kit has line from brake switch direct to caliper, a little bit thick beside the fender. I use lines with the stock model tubes from calipers now since its really tight on right side, fender - fork (Kit from Slingshot).
Connect everything, fill brake fluid. Tank and painted areas nearby covered with an old clean cotton sheet.
Pump the MC, using brake. Open up the bleeder screw on caliper. Easier if there is a tube connected on it leading the fluid in a jar. Press brake lever in, let it flow from caliper via the tube. Close bleeder and release brake lever. Pump some again, keep lever in while open the bleeder, let it flow. Close bleeder and release lever. Fill fluid before it can take air.
Do this sometimes until it stop coming bubbles down the caliper bleeder. I have noticed that air will bubble up via the MC too. Do not pump too hard with no cap since it squirts. Pump here until bubbles stop coming at MC too.
I thought that dual should be tricky, but no problem. My MC is a few years old, cheap aftermarket from DSS, calipers have new seals and pistons. One caliper is DSS aftermarket caliper, a copy.