Well. This Idea is based on the Laser Inihibiting Arrow IV Submunition. Instead of delivering the inhibiting gas via a Missile, why not build gasexhausts inside a mech and use the gas as ammo?
I would go with a weight of 4 tons (half a ton for each location) and 1 Crit slot per location for a total of 8. Gas Ammo, similar to the Laser Inhibitimng Arrow I would set at 5 per ton. The pressurized gas can explode with a damage value equal to the remaining "shots".
For the use: A Mechwarrior must decide at end of Movement Phase of a turn to use the system. If he do so, the gas is released and the inhibiting cloud is in effect. Treat this as if an inhibting arrow hit the hex the Mech occupies. Meaning the +2 hit penalty for Lasers is in effect as well as the smoke effect. This goes for own units as well as the enemy.
The idea behind this is to have a system similar to the Blueshield against Lasers. Instead of halfing the damage, the chance to get hit by Lasers is less.
Thoughts?