You are quite correct, fried…it’s difficult to foresee all possibilities…..and they are not cheap…. BUT…they are a LOT cheaper than an instrument cluster that may have been repairable if it weren’t sprayed-down with a dry-chemical extinguisher.
I‘m thinking of my older brother who bought a dry chemical ext. for his car. One day he was driving along and saw “smoke” coming out from the AC vents in his dash and pulled out that extinguisher and discharged it into every vent in the car.
The dealership charged him $2200 in labor to disassemble his entire interior and panel and heater/AC coils and clean them out and put it all back together. Diagnosis: No evidence of a fire.
I asked my bro‘ if the “smoke” had any SMELL to it…. He said “No.”
I said, “I hate to tell you this…but in a vehicle fire the smoke will have a nasty SMELL…. but condensation “fog” from an air conditioner is only moisture and will not.”
(When my sister and I talk about our older brother we sometimes think Daddy may have pulled-out early.).
Continental Airlines have twice made emergency-returns after. takeoff from Houston Intecontinental when the cabin alerted the crew to ”smoke” in the cabin…. which turned out to be condensation-fog from the overhead vents.