Oh, sorry, I was working with the assumption that fuel tanks would be re-sized. Most WarShips have plenty of cargo room for the change. DropShips might need a big redesign. JumpShips...well, if they could work at an extreme fractional thrust would be fine for stationkeeping.
You'd have to make a new rule for station-keeping where vehicles at the jump zones (i.e. not near a gravity source) can spend any amount of time they wish at that location, with no short-term noticeable fuel use. (10^-6 Gs means that for ~400 days you'd only burn 4 * 10^-4 burn-days of fuel). You'd burn fuel to maneuver into the jump limit, decelerate, then later thrust out of the jump zone, but that might only be .1 Burn-day.
This way you can have Jumpships hanging out just inside the Zenith/Nadir jump zones, slowly absorbing solar energy, and when it is time for them to leave they thrust outside the jump limit, attach Dropships, and jump out.
Phrase maneuvers in terms of Burn-days, and that way players can determine which one to do.
Driving around at 0.1G constant acceleration is still relatively fast for in system transit, so DropShips wouldn't need too much redesign. And JumpShips don't really need too much for station keeping, either. As I recall, gravitational fields near a typical zenith or nadir jump point are on the order of 10-6...
Going at .1G means it will take ~3 times as long as going there at 1G (going meaning accelerating towards then decelerating towards the destination), while burning ~1/3 the fuel. The specific multiplier/divisor values are:
k = [1G / (your acceleration in G)] ^(1/2)
Transit time = (Time @ 1G) * k
Fuel consumption = (Fuel consumption @ 1G) / k
To make the math easy, we could prefer to use 1/n times G, where n is a square value (4, 9, 16, 25, aso).