Thanks for all the feedback. I think I'll simply give it a try and mount the canister to my O2 bottle. The only thing I don't like about this is that my light canister becomes the most exposed point of my rig. I guess I just have to be careful when I go cave diving
The main reason why I want to move it away from the belt webbing is that I want the extra weight further up on the rig, so that I can improve my trim without adding extra weight.