Engine Gimballing Responding to Roll Commands

[shynung]

I noticed that the thrust vectoring, or gimballing, of all types of engines, only respond to yaw and pitch commands (W, A, S, D), but not roll commands (Q, E). This happens whether the engines are single-nozzle designs (most stock engines), or multiple-nozzle ones (LFB, KS-25 cluster, RAPIER). As a result, a heavy rocket at launch will respond predictably when turning around, but almost never actually rolling when commanded.

I wonder, is it difficult to make Mainsails at opposite sides of a rocket gimbal themselves in opposition to their counterparts in order to roll the rocket? Or the individual engines of the KS-25 cluster, for that matter?

_{Also, does anyone knows of a mod that enables this?}

Edited May 13, 2014 by shynung