What I wish had been done with stealth armor, is saying each point of heat you generate over the initial 10 counts as a penalty against the stealth rating. Essentially if you are putting out massive heat, the stealth capability is overwhelmed.
Battlemech Ninjas at that point, each trying to keep their heat low, but if they aren't going to be observed (or will one-turn kill the target) they open fire with everything.
(Now I'm getting mental images of Mechs walking on tip-toes, with a black face mask, and carrying a HPPC with capacitor.)