I think that this fix only focuses on specific weapons (PPCs & ML), something could be implemented that is much more effective on a broad scale that helps to prevent High-Heat Alpha strike builds.
I believe that leaving the dual AC20 / Gauss out of the conversation is fair as these weapons weigh a considerable amount more (14 & 15 tons respectively) than ML, LL, and PPCs; especially when you consider the amount of ammo needed to effectively utilize it on the battlefield and the quantity critical slots consumed by these weapons.
Here's my idea:
1.)
Heat Management
Generating excessive heat within the pre-established time parameters (1.25 seconds) creates penalty, this time value is selected as lasers generate heat continuously through the 1 second 'burn' time.
Q: What is 'Excessive Heat'?
A: Excessive Heat - I believe this should be based on the heat threshold of each mech. So, instead of getting penalized for firing 'Y' Weapons of same type simultaneously, you get penalized for generating X% of your total heat threshold (referred to as THT from here on) within 1.25 seconds.
2.)
The Penalty
You've exceeded
X% total heat threshold in rapid fashion, prepare to suffer! For demonstration purposes I will use an arbitrary value for
X (40%) here, it is not necessarily my intended value for implementation, but it's not far off, as this would make Tier 1 somewhere around 3 ER PPC's fired simultaneously with 15 DBL HS, so it is quite foreseeable that a Stalker with 20-22 DHS could fire 3 PPCs with no penalty, but that 4th might start doing dmg.
1.) Penalty Tier 1, 40%-47% THT
You've melted a Heat Sink, congratulations! Now you've effectively reduced your heat dissipation and lowered your THT.
2.) Penalty Tier 2, 48%-55% THT
You've now damaged your internal structure and armor (in addition to Tier 1 penalty).
3.) Penalty Tier 3, 56%-65% THT
Yeah, wtg buddy, that'll cost you an additional Heat Sink, do critical damage to components, structure, and armor, and is likely to cook off your ammo. Enjoy!
4.) Penalty Tier 4, 66%-75% THT
Total penalty of 3 Heat Sinks, damages structure, components, armor, engine, etc. You've considerably lowered your THT, doing that again will kill you more than likely.
Over 75% THT = One crispy pilot served fresh to the enemy team.
3.)
Overheating
I agree that 150% is far, far too generous of a maximum heat level before penalty kicks in, Exceeding 125% and you're cooked, over 105% THT and you start damaging components on the mech, so this should be the last ditch effort of a pilot who is almost certainly dead but attempting to save a teammate.