I think wrapping the 7 footer around the head (DIR) negates any advantages for the new diver. If you need air and he's unwrapping and gets it stuck you are SOL.
Try it, you might be surprised how easy it is. I dive the 7 foot hose (looped around a reel or other item on my right hip), up and around the back my neck. If you were very short, a 5 foot hose might be OK for the same routing. It's rigged that way because you really can grab it and donate it in an instant, just by ducking your head. No unwrapping necessary.
In regards to other tech solutions I wear a 5 inch knife on my waist strap where I can reach it with both hands. ... Shears? Overkill unless diving in areas prone for fishing line and other entaglements.
Uh, I'm a bit afraid to ask why you are carrying a knife, if it's not primarily for entanglements.
Also, I don't understand why a $5 pair of shears (which are very handy topside as well) are overkill. I carry a set, and have an EZ-cut on my computer wrist strap.