The big consternation seems to be large, accurate alphas. Why not incorporate a table top mechanic that applies fairly to all 'Mech chassis, encourages less min-maxed builds and doesn't impact brawlers anywhere near as heavily as it does stand off builds?
My suggestion is a scaling accuracy debuff, proportional to your heatscale. In table you you suffer a gunnery penalty as your heat rises. This can be blamed on heat expansion warping weapon mounts, heat haze and smoke interfering with sensors and sensitive electronics struggling to cope with thermal overload.
In practice, I'd suggest this take the form of a wandering crosshair - similar to MASC but smoother and more even with larger sweeping loops rather than a seizure inducing stutter. To keep it balanced for LRM and ATM's, I'd suggest losing locks over a certain threshold and making acquiring lock take longer as heat builds up.
Gauss rifles already have an inherent inaccuracy, charge time and recoil, that can be overcome with skill. A strong but relatively predictable motion of the crosshairs would still be managed with a skilled and steady hand, but repeated high alphas at range without cooling down will become less effective.
Light and medium 'mechs that rely on hit and run, or getting into knife fighting range would be relatively unaffected as long as the crosshair sway is smaller than "Arc of 'Mech" at point blank range. Brawlers will get a better chance to close, but high heat brawlers will still suffer slightly. LRM 'mechs will just need to throttle their fire more to manage their heat.
This doesn't require a change to ghost heat. I'd also suggest allowing targeting computers to reduce crosshair sway. Encouraging tonnage to be spent on something other than more weapons.
Edited by Gretik, 31 July 2018 - 04:38 AM.