I quite agree with kilemall, but the trick is to make rule-systems that are expressive without being crazy complicated. KISS.
Hence I would say avoid too complicated power games.
LBB5 is reasonably expressive, without being too complicated IMHO.
Otherwise we would all be playing TNE and discussing the finer points of FF&S?
We're mostly on the same page here, though I prefer the LBB2 drives and combat paradigm -- Jump is big and costly, maneuver is small and cheap but isn't necessarily decisive in combat.
The problem in this case is that LBB5's power rules aren't granular enough for edge cases (while LBB2 studiously averts its gaze from the topic). That's fine for nearly everything one would want to do.
Underpinning this is the assumption that power is cheap and easy because there's fusion. In LBB5, any power requirement less than 250MW (1EP) in a starship is treated as a rounding error (small craft maneuver drives are the exception). Even the power for 1G acceleration is free -- it's already subsumed in the minimum power plant requirement, and you don't save any power by not installing a maneuver drive.
The rules thus don't have to cover cases where "energy is not easy" is a design constraint, because in-universe it almost never is. This is distinct from "energy is not easy" resulting from a crisis (power plant failure, stranding after a misjump, fuel tank damage, and so forth).
As a case in point, the International Space Station has a pressurized volume of about 68 Traveller Td, and uses about 102 kilowatts. (This is the average power output of its solar array, buffered by batteries for the about 1/3 of the time it's in Earth's shadow). A Traveller spacecraft that size needs 175
megawatts baseline power...
Obviously, artificial gravity isn't free, and neither is the implicit radiation-shielding field that keeps spacers from getting cancer*. But 1700 times as much power as TL 7.5 basic life support and climate control seems a little steep. It really doesn't matter for most Traveller ships, since they'll always have a power plant that puts out that kind of energy just ticking over at idle speed. It only matters when you're building one that doesn't have drives and weapons that use power in quarter-gigawatt increments.
*But in most versions of Traveller, mass is free because drive effects are volume based. You could add layers of lead shielding around everything and it wouldn't make a performance difference...