Interesting to read, but in the end you really should set a custom white balance. Much easier to get the other non-red colours to show up in your images. Astrophotographer Jerry Lodriguss article link ...
http://www.astropix.com/html/i_astrop/customwb.html
Note especially from that aticle ... shoot images for no filter, as well as every filter you are going to use with it as they all cast a different colour hue over the image. Even your unmodded camera you should shoot a CWB for it with every filter you are going to use with that cam.
BTW, while I've got a digital grey card, before I had that I set my CWB by shooting straight down at noon at a bitumen road surface. I shoot one which is fully illuminated bitumen and one fully in shade. I actually found the one in the shade (so a much darker, almost black surface) yielded better images at night on the scope. But you may find otherwise? Try both. Very simple and easy to do. Do not put on a lens as you want it totally out of focus. Pointless putting on a lens and focusing on the bitumen as all the slight blemishes and reflections off the surface will create a speckled CWB. Totally out of focus means the sensor see's just a flat grey edge to edge. So you can go try it out right now. Cheers