The idea of battle smoke is a great one. Needs development work.
I designed the original "Supersmoker" that Phil sold, and have built a lot of smokers for tank, tugboat, train, battleship models etc etc.
The problem with oil based smokers (like the WD40 one you referenced) is that the oil residue and hot vapors destroy plastic and paint finishes. Bad for a nicely finished model.
So water/polyol (fog juice) smokers became the design of choice. They also operate at lower, safer temperatures than oil based smokers.
The fog juice vapor, when free to dissipate in air (eg as exhaust smoke) doesn't condense much on surfaces, and when it does, it doesn't usually cause any damage to or change in appearance of a paint job. Any residue can be cleaned off with a moist rag.
When the vapor gets trapped inside a model, it will condense. Same effect as spraying sugar water over everything. The result is mold, corrosion and a general mess. That's why smokers are built tight - hopefully with no leaks, and with discharge outside the model only thru the tubes.
Attached is a picture of the rear axle area of my Tamiya KT. The smoker is a mini-design I made. It has a very small amount of "fog" backflow. The tank doesn't have many hours (maybe 20) of run time. You can see the effect on the axle (steel) and on the body pan. Even aluminum stiffening struts have a cloudy surface film. I've made and run a lot of smokers and have tested a lot of fluids, etc. Internal damage - or at least a mess - will eventually occur even with limited internal "smoke" release.

A possible approach to a battle damage smoker would be to use the existing exhaust smoker (given limited space for a second smoker), but have a second evaporator resistor/wick that gets powered when the "fire" starts. That evaporator could be high wattage to produce more smoke. (The regular exhaust smoker wattage is kept low to produce "just enough" exhaust effect and to preserve battery power usage for running/battling.) Once decommissioned, the use of battery capacity can go to high smoke production since the power is no longer needed for running. Once the high output evaporator kicks in, a simple valve can duct the extra smoke thru tubes to external smoke ports.