Ok, so we have an opposite here.
When you image without a glass in the noise piece Marc, how do you control the IR bloat of the stars Gama talks about? This sort of answers my own question, which is to use my Astronomic IR filter in the wheel for RGB shots.
Ha, SII & OIII should supress the IR, at least I've never used them with my Meade DSI Pro II, but that is a mono camera.