What I tried:
Was just positioning both my mounts together up front. That will be about as solid as you can get clamping them to either the slots in the action or the Davidson type mounts. I shot both rifles that way for a few matches and they seemed ok.
A manufacturer and person of some note came up to me and said, "you are going to get into trouble with mounting your scope up front only". Sez I, "I haven't had any trouble so far". He sez, "look through scope", which I did as he lightly touched the bell just above where I was looking.
You probably won't have to go to all the trouble of mounting the scope that way and touching the bell whilst looking through it. I immediately changed mine back to one in front and one in back.
I have stated previously that I bought two of the H&R Handi Rifles that have the cantilever scope mount on them. I could not keep a zero wirth them so gave up on the rifles. I did not try hanging the scope from only the front with them but it just doesn't seem a practical thing to do; to me anyway.
While I think having the scope only mounted at one point looks sexxxxxy, I have decided it might not be that best thing to do, in the long run, gravity being what it is and the tubes being glued together @ the turrets and all.