I believe the Belgians use beet sugar simply because it's cheap and available there, not because there's any detectable difference between it and cane sugar.
That's true. Cane sugar would do about the same thing. The point was that their sugar might be alkaline from the processing and ours isn't. And if it has traces of protein in it, either from the beets or from the bonechar, it has everything it needs for browning and caramelization.
This is all theory. I'll put it to practice real soon and see if it washes-out. Tomorrow is my wife's birthday, so I won't get to experiment until Saturday or Sunday.
I've seen too many videos and blogs with people boiling sugar and a little citric acid or potassium bitartrate for *hours* just to get to a light amber without much flavor. I think we are doing it wrong. First I started to go the burnt sugar route, but the DAP thing looks a lot closer -- but maybe not quite there yet.
I have no idea about adding the wheat flour. Other people use DME to get a little protein. I don't have any DME, and flour has twice the protein so it won't take as much. If it works, that's my contribution.