[(E)]

I think fuel quality would be a good addition.

I was just playing with a design for a long range trader/scout (a worst case kind of example I know) SM 8

systems I wanted to include where an additional sensor array for the "off the beaten track" work, a Hanger bay and a refinery to refuel at gas giants, engine room. with cramped space for a crew of 8 ish there was 7 spaces left for fuel and cargo, or six spaces with more "scenery" space.

Say 3 cargo spaces and you have 3 or 4 fuel spaces, which I thought was a bit lite as it means only 8 to 11 deep jumps.

Its definitely functional but 2 or 3 spaces for fuel seemed closer to what I envisioned.

On a side note, do we want the number of jumps between systems to be less or more varied?

Edit

travel example
Ship with 3 tanks fuels at a 'Hook fuel = [9]
reactionless thrust takes ship out of gas giants gravity well
shallow jump to "clear space" (?) [8.9]
jump to close system takes 2 deep jumps and say 2 shallow jumps to get to asteroid mining habitat [6.7] (no gas giant and planetary conditions make getting water tricky)
jump to planet [6.6]
jump to other habitat [6.5]
Jump to clear space [6.4]
jump to close system takes 3 jumps and 3 shallow jumps [3.1]
one last shallow jump to get close to the hook [3]

too extreme? or what if it was a longer jump?

not sure about the different classes of engines. something similar maybe, drive configuration(?) ("retool the converter ring for a long jump""that'll take hours" etc)