You're right, it can be a problem. I know I've folded out of turn once or twice by accident in seat 1 because the player in the 10 seat is in my blind spot.
Anywho, as a dealer (I do functions and bars, not casinos
FWIW), if someone asked me politely to lean back so they could see the player opposite I wouldn't mind - if you're still weighing up your decisions, then I'm not doing anything much that requires me to reach the table anyway.
It's down to each individual dealer, of course, but I couldn't see there being any harm in asking.
Otherwise, there'd be nothing wrong with leaning forward and looking around them.