...whether you could beam over...
Well, David Marcus clearly says "You can't".
I always took "You can't" as "You can't stop it
It being Genesis. I've never read that line as you couldn't beam over.
I suppose you could take the line reading that way but I always assumed he was talking about turning it off. When David says "You can't" he means:
"We forgot to put an off switch on it"