Role playing, unfortunately, doesn’t model real human behavior very well and of course the players want to optimize their chances of surviving combat, so if the weight limit is 51.3 kg, you’ll get statements like "and my character is carrying 6 extra magazines of ammunition, with four rounds taken out of the last magazine so my load is 51,300.00 grams". And then that’s what they carry for the next five weeks, awake or asleep. 

In reality, if a character on a merchant ship has never once needed her sidearm in 10 years of work, and there is no requirement to carry it, it’s pretty unlikely that she’s strapping on her sidearm every morning when leaving her cabin for the bridge. This is, in part, what tactical surprise should account for - not just that the target is disoriented and does not have a plan to deal with whatever’s happening, but that weapons and equipment are less likely to be immediately available. 

It would be nice if there were more behavior rules, to some extent. Presume that unless otherwise explicitly stated that a character dressed in his her her lightweight uniform (or whatever) when working shipboard in the tedium of day to day ship operations. 

There should be more advantage given to unencumbered characters as well, or the players should more realistically role play their characters. 

Thank you.  That's exactly why I put it in and held the players to it.  IMO a lot of Traveller games miss the opportunities this kind of thing.  Not just for being mean about what equipment they (don't) have and so on, but also for role playing.