Okay, I'll give you a tip... you should already know this, but you can change your mission "on the fly," so to speak, by pressing the select button at any time during play. As a result, Twin Galaxies does not specify which mission(s) their scores are recorded for and would presumably accept a score that used any mission(s) during play. Now, as you know, there are different gravitational forces put into play on different missions, with the main difference between Training and the rest being the presence or absence of atmospheric friction.
With all that said, here's the tip: you can use the above information to your advantage by changing the mission (and thus, the physics) mid-game, and as soon as you realize that the closest 5X is on the other side of the peak and much farther away than you'd like. In fact, try this out: start a game on Training, and once the game starts, don't touch the controls at all. Now take note of where your module crashed and then start a new mission on Cadet, Prime, and Command, each time not touching the controls and each time taking note of where you crashed. See the difference? Once you've done this and seen the physics in play for yourself, you'll understand just how easy it is to conserve a lot of fuel by manipulating the game's physics at your whim. The bottom line here is that there are more buttons available during play than just left, right, thrust and abort ;-)
Anyway, for me personally, I no longer do any of that strategical garbage because I think it's cheap, even though it would "count" for Twin Galaxies. Actually, I don't really play for score at all any more, for whatever that's worth - I exclusively play on Command and, at this point, can land on surfaces that aren't even 100% flat...
Well that was long-winded, but hey, you're the one who asked!