Peltier camouflage tiles to the rescue. You will be cold on outside AND you can keep warm on the inside. There were demos where a tank was camouflaged in infrared as a cow or a car.
Ah! Sounds like hesitation! If you are hesitating to ID a target that could mean you're about to die or you're lucky. Camouflage doesn't need to be perfect, it buys time. Those with better camouflage are more likely to have the advantage of seeing their target first.
It's also why stealth aircraft don't need to be perfect- they are more likely to see their enemy first.
Now you have to go around shooting every cow, terrorizing locals, and giving the enemy ammo for propaganda purposes. Shooting every cow also gives away your position.
They are already under development. The main issue is that modern anti missiles systems require a ton of power. So even going into a passive turret mode needs engines. There's a case to be made for having diesel engines so you can run the turret of a few cylinders and not have to have a all or nothing turbine.
It will always be a trade off between lower signature and protection/awareness.
Active protection systems have radars that will light you up like a Xmas tree, tanks also have a lot of EW gear on them that even before hardkill APS became common used a ton of power and increases their signature.
Silent/LowSig mode is just another tool in their toolkit. If they know that the threat landscape allows them to go into low signature mode safely and that it would improve their combat effectiveness they now will be able to do so.
