I had a similar idea for a "realish" version of the Battletech universe but without changing any of the units or rules. The concept was.
1. Lagrange Points are the standard jump points so Jumpships emerge closer to the target.
2. The listed tonnage is dry mass, with every ship having a wet mass of liquid hydrogen equal to their dry mass. Eliminating that pesky mass fraction problem.
3. Drop ships and Jumpships have a "cruise speed" of 0.1g burning LH2.
4. The tonnage set aside in the existing states for fuel is LOX tankage. Used to augment thrust in launch, landing, and combat. Used as in the combat system. The high efficiency transit mode doesn't exist.
5. We ignore the decrease in weight increasing acceleration as to complicated for tabletop. Something something structurally integrity.
So in short, lower the acceleration of dropships outside of combat/atmosphere. Bring the jump point closer. Fiat a realistic mass fraction. Definitely don't run the math and if you squint at it it feels more real without requiring a lot of rocket science on the tabletop.