I wouldn't quantify MgT as an LBB rehash, they are their own things.
Not being a detailed student of the system, I just saw variant of the LBB stuff. Simple trade, simple starship design, "same" character generation. Mechanically and systemically, it seemed very similar to LBB. The RPG mechanics may have been different, I'm not really a cognoscenti on RPG mechanics.
TNE advanced equipment to a whole new level by expanded on what was done in Striker with FF&S, making it fundamental to the system. FF&S was written in cohort with TNE, so as to design all of the standard ships, vehicles, and weapons and such. As will all things there's an evolution, and bugs, and gaps, but more so than not they started from a clean slate and worked up. Similarly with combat and how it applied to all of this. If you fire a Body Pistol at a Starship, TNE will tell what will happen. Similarly, if the Starship defends itself and pumps a 150MJ laser in to the shooter, TNE will, sorta, tell you what happened.
In that sense, TNE advanced the entire platform with a solid bedrock of "Here's how the physics mostly work in our universe" and built everything up.
GT: Far Trader pushed trade to a new level introducing, albeit simplified but still detailed, economic models beyond mere "lists of stuff that cost XXX".
First In, World Tamers Handbook, World Builders Handbook all helped move forward the states of the art in to terms of world building systems, each contributing in their own way.
I honestly don't know if MgT has done much in any of these areas. It just seemed more of the same old, same old, in new books with current publishing dates.