Definitely T10 runs cooler than the T9 or the T6, however that doesnt mean one cannot build a non-thermal-efficient T10
I worked pretty hard to engineer my T10 to
not cook itself.
Reactor is fine and dandy, engineered the thrusters to likewise put out less heat when using 'em... So I don't accidentally turn my ship into an oversized hot-pocket when thrusting towards stations or using 'em to git out off the surface of heavier-grav' worlds.
RN the only times I see a heat warning is if I fire off the three-shot grouping of Plasma Slug Accelerators repeatedly back-to-back...
Or fire my oversized, long-range pulse lasers
(medium & large hardpoints) at a target for more than a minute or more.
Usually that warning is pretty short lived tho', as those heat levels are either the result of LONG firing times without rest or from the sudden heat spike of launching several plasma slug shots at once.
But given my ship's turn speeds and how rarely enemies can endure the damage output it can pump out, that rarely occurs.
Worst comes to worst, I can push a pip or two into Weapons from System...
Since if I'm not under fire and my shields are topped up, there's no reason
NOT to pump more las' and plasm' into the enemy.