In my post on heat (here) I try to explain about heat radiators in Traveller (specifically why there are no heat radiators in Traveller). If you don't want to read the post basically Traveller tech opens a wormhole and sends the heat from the power plants and drives into jump space. This enables somewhat stealthy ships.
This also bothered me because I like some concessions to reality. Things should not come with no strings attached but attaching complications to an idea falls squarely in my wheelhouse. In this case real world tech provides a problem.
Basically heat radiators must be optimized to work at a given temperature. If you are radiatingn heat from something like a fusion reactor you're talking about a radiator and conducting equipment operating at several hundred to a thousand degrees or more (C.) I'm going to assume the 'jump-radiator' works similarly. So you can't hook your life support system up to it. Heat likes to move towards cooler objects and you will simply cook your crew if you hook your life system radiator into the reactor radiator system. If you've read my posts on Traveller fusion reactors (here)you know they probably put out a lot of heat. A Scout alone would require a radiator system the size of a dreadnought to avoid melting.
So Traveller ships do have radiators of some sort for the life systems and thus are not visible for light hours when they turn on their drives.
But wait there's more. Since we're dealing with the much smaller heat signatures of a life system instead of radiating it you could simply pump it into your liquid hydrogen fuel. this would allow a ship to remain stealthy for hours or days. It also fits the artwork you see where ships have those glowing circular wells where the rockets should be. They are radiators pointing away from the enemy and linked to a venting system for the heated fuel (sometimes the ships have a slight glowing trail.)
Shooting off lasers probably uses a third radiator system (somewhere between the power plant and life system in temperature) or vents hydrogen or helium. But by the time you open fire you pretty much no longer have sneaking around left as an option. Blast away!
A commando ship (or even a drop capsule) might take this a step further. Put the crew into low berths and turn down the thermostat. The ship flies to it's destination on robotics and then the crew is thawed last minute. During re-entry. Probably taking fire. Expected to fight from the moment of landing.
Hey it's no thing Mr. Marine, frozen watch does it all the time.