Yeah but the payload was 30,000 lb of explosives. If the b-17 chassis could handle 30,000 lb of explosives surely there's a way to modify it to take a 12,000 lb bomb.
That said it's probably a lot of modification and wouldn't make economic sense.
No it was not 30,000lb or anything even close even when completely stripped down as an Aphrodite.
A Maximum 12000 lb of explosive for a trip of less than 400 miles....
but basically a blast weapon having no ground/armour penetration like a tallboy/grandslam.
BTW the normal bomb load for a B-17 was only 4,000 lbs for a flight of 1,000 miles.
A
Mosquito could do as well and at greater speed and far less than half the cost.