FYI:
The (unpublished) mod I am working on is based around 100 kT/2 MP engines. It uses a mixed system to scale the engines:
The baseline is a 1000 kT ship.
Mounts for ships ranging from 10 – 900 kT.
Engines numbers/Engines Per Move for ships ranging from 2000 - 9000 kT.
I removed the supply storage ability from the engines so that a ship’s supply capacity was smoothly scalable and more under player design control. To compensate, I added more supply storage component options (normal, conformal, and drop supply storage) and in a variety of sizes. I also tweaked the kT/supply storage ratio for supply components. The % of kT and other attributes to move any ship speed = X is constant through all the ship sizes. I also did the same for the vehicle control components.
I am happy with this approach as it meets most desiderata.
Very minor problems with this approach:
Some casual (to me) rounding errors.
The hard-coded repair system does not scale.
You need to scale-up engine damaging weapons w/mounts for them to work against all but the smallest ships.
The ship design process is more challenging and intolerant: you need to remember to use mounts for ships <1000 kT and to add supply storage to all designs. I have done everything I can to minimize this issue, including extensive documentation.
The idea is relatively mature at this point in the mod process, so I would be open to sharing specifics and accepting criticism if anyone is interested.
Gecko