Rocket-assisted takeoff would not solve every B-25 limit

How much more fuel or bomb load could rocket-assisted takeoff have given the Doolittle B-25s?

Perhaps some extra bomb weight, but tank space and the airframe's maximum load would still impose hard limits.

Rocket assistance might allow extra bomb weight during a deck launch, but the possible increase remains uncertain. Additional fuel would need tank space inside an aircraft already modified to carry more fuel. More launch thrust would therefore solve only part of the problem. The amount the airframe could carry would still limit the load.