I'm not sure a 'gear' solution is the right answer guys.
There's a habit pattern that is somewhat concerning, in Battletech-a niche is identified, a new piece of hardware pops up-that should've been there all along, and was implied as there from the start, or was silent but assumed (ECM being an example, also rocket launchers and various weight Machine guns).
"Why wouldn't you use a Warship for that?"
that's our question, if I'm reading the last few posts right.
It's a decent question. the answer that comes to mind for me, is something more fundamental than "New and improved ADA defense tech that the Clans get first!!! and bEST!!!"
or you can say "...clans get the best of after examining one and doing a better version" if you start it in the Inner Sphere.
Two ways I see to go with it; Orbital Bombardment is DESTRUCTIVE, and as we see with aerial bombing and with artillery, it's likely to be somewhat to very inaccurate.
Instead of a dinner plate blast diagram, you're dropping Turkey Platters on the mapsheet, but randomly.
That's consistent with both tube arty, and with aerial bombardment (bombs dropping on level bombing, as opposed to strike).
Basically, if the target is city-sized (or Island size, as in the Admiral McKenna story) it's the beez neez, but if you're trying to hit something small and mobile, through atmospheric lensing, pollution, smoke, clouds... well...if you don't mind a footprint the size of a medium sized county? then it's alright, but not ideal-your odds of hitting your own guys are too high and to limit that, you gotta get down where you're burning fuel just to keep from crashing...which makes you vulnerable to pretty much everything since you're not going to have much potential energy left to maneuver.
Makes your indomitable warship a kind of fat, slow moving (if it moves at all) target for everything in range. Not just special missiles, but fighters, fighters with bomb loads, fighters who can release bomb loads in a toss-bombing, bigger field artillery, and so on.
about the only tweak I'd use, is to require a PSR for every combat round your warship's doing that, with increasing difficulty reflecting the fun of trying to hold something decidedly non-aerodynamic that was never meant to be that close to a gravity well, steady while your crew try to parse through atmospheric noise and ground clutter (and frantic calls for support from your ground units) to try not to hit the friendlies while playing 'erase the enemy'.
that vibration should probably also impose a targeting penalty, since you're trying to hover in turbulence that's going to get worse over time.
IOW nobody said the Smoke Jaguars aren't good shots, just that they chose a city as both target and backstop, which is a moral, not technical, choice.
The alternative is, hanging back and hoping volume of fire gets your shots 'kinda close' to the target. Ship sensors are made to look out across vast distances of hard vacuum.