I do not think autoadvance it is needed or even desirable. The RCEXL ignitions come with it. Is it being suggested that I open up the ignition to modify it? If it works as is why not use it as designed? The modelelectric coil and associated parts would cost more than the RCEXL. I see simple ignitions here:

http://www.modelflight.com/larrydavidson.html

The voltage is only up to 3.6 So I must use a second battery pack, adding unneeded weight. That also means I can't use the opto bec to switch the ignition on and off. It just seems much simpler and less chance of RFI to use the RCEXL.

I know all about kickback. My 65cc Stihl 4-stroke got me real good a while back. At first I thought I might have broken a finger. I made the attached glove. I glued heavy belt leather to the back of a work glove with shoe goo. It have saved me pain on several occasions since I made it.