Thanks for maintaining this list!
I posted this in the 1.28 bug topic, but I it looks like it got missed.
Quoted from RobF:Flashing combo shots are not awarded specifically for the Demon shot. I used to think it was only related to Deuce as that song has the bug of awarding non-lit shots. However I have confirmed that other songs do not give a 2x combo for when the shot is flashing either. I am not sure if this also applies when you have set that shot for the 2x song completion multiplier.
I have yet to confirm in 1.30.