Outside of extreme niches, every beam laser is, or should be, efficient or long range, with thermal vent.
Agreed. And due to issues like this, weapons and weapon engineering need another look, in my opinion.
Things like no-downsides mods or specials - efficient and thermal vent, mostly - are too good and it's problematic for other modifications or even other weapons - like incendiary multicannons, which are in such a niche they're nearly pointless. Heat in weapons especially needs another look. It's a major mechanic and balancing factor in several weapons... but is also able to be completely ignored as a factor in many of those weapons, due to engineering. I like the idea of being able to cool down hot weapons with engineering, but if you're going to make it to such an extreme that heat can be irrelevant as a game mechanic, you're better off just discarding the mechanic and going another way for balancing.
Making balance mechanics optional just increases the difficulty of achieving good balance to an absurd degree, and it's not viable.