[Spaceships] Control Rooms With Reactionless Drives

[scc]

I've seen it said a few times around here that Control Rooms come with a small Delta-V reserve (0.3 mps) to represent the RCS systems that they include.

That's fine for chemical propulsion systems, but what about ships that use Reactionless Engines? Well in that case Delta-V doesn't matter (I'd assume that the Control Room includes a Power Plant that also powers the life support system, you worry more about running out of air then juice for the drive) but how much thrust can this system generate? And can I pay to get a more powerful drive?