I like TNE because they "scienced" it, however imperfectly. But they tried. They tried to apply the same "rules" from switch blades to meson guns from a "sorta" material science perspective, no easy task. Gave the game a "harder" sci-fi edge.
Did they unnecessarily complicate it? Perhaps. It's supposed to be a game after all. The laser design sequence alone makes the mind go spinny.
Actually you could say that it hearkened back to 1977, or perhaps HG1, where ships were assumed to be using fusion rocket like things.
I kind of disagree. As I like to say, for many of the fundamental universe mechanics in the game, over time (via rules, JTAS, MT), the systems evolved and gain clarity, but not really revolutionized. M-Drive has always been a power thing, not a fusion blast thing. I don't see some huge paradigm shift from '77 to '81 forward.
For all practical purposes, the M-Drive was never a constraint. "effectively unlimited" was the term in '77 Book 2. In '81 Book 2 it was "Power plant fuel under the formula (10Pn) allows routine operations and maneuver for four weeks." And always note that the fuel is based on the power plant, not the M-Drive, with the only requirement being the power plant being at least as big as the drive. Even with the consumption rates in Beltstrike, the Seeker (the modified Scout ship in Beltstrike) with 30 tons of fuel, if you allocated 10 tons of fuel towards powering Maneuver, that's, to use TNEs term, 5000 G Hours of fuel. 208 days of acceleration at 1G. Since it takes about a week at 1G to get to Jupiter, that's 15 round trips out and back from Earth.
Contrast that to a TNE Free Trader, which has fuel for 28 G Hours (not including Jump Fuel). To run out to Jupiter and back using that fuel alone (and not refueling) is a 70 day journey for the Free Trader. 7 hours of acceleration plus 7 hours of deceleration, both ways.
There's a vast difference between requiring power and reaction mass. Maneuver drives have always required fuel, but in CT, it's fuel used to power the power planet. In TNE, it's fuel to be pushed out the back end of the ship. TNE made M-Drive fuel a First Class problem, in contrast to CT where it's basically a load on the circuit breakers next to the refrigerator and microwave. It's easy to consider the Beltstrike consumption the same way you'd consider how much gasoline is used to power a generator to power bright lights.
Mechanically, it's kind of moot. A Free Trader needs enough fuel to push it 100D, not span entire solar systems. Obviously there are jump shadowed planets that require more flight time, but, those are pedantic edge cases in a world of door kicking, big game hunting, T-shirt world adventure. IMTU those traders would either dock at a very high-port at the outer 100D limit and let the intra-system network move things to the main world on their dime, or at least the ship would be able to top off and burn their jump fuel in to the main planet. Burning jump fuel, Jupiter to Earth, one way, is only 13 days on the TNE Free Trader, only twice as much as a 1G burn the entire way. Not crippling to say the least.
For "normal" planets, there's more than enough fuel for full burns to 100D and back. In TNE, any "real" adventure ship would be over built to bring extra maneuver fuel just to ensure a better chance of it not becoming a problem. Most TNE combat vessels have twice the fuel reserves of the traders.