if this meter had alkaline battery failure then the pcb needs a vinegar-wash.
alkaline batteries dont leak liquid, it's a vapor and it gets into and under stuff.
its not a vapor, its a aerosol. The only vapor they make is water. What they can do is spritz a mist that settles on various parts, and leak liquid that wicks up surfaces, and wicks up wires (like a sponge).
If it evaporates into a vapor, its water that leaves the electrolyte caustic chemicals behind as a solid.
The battery consists of various inorganic chemicals, water and some specialty additives (surfactant, etc)
If the battery were to leak out, and then peacefully dry up in a puddle on the bottom of the battery cavity, you would only have humidity damage in the meter. But usually it starts misting (hissing, high pressure) and it makes corrosive fog.
vapor is actually evaporated stuff in molecular gas form. A lead acid battery WILL make some small amount of corrosive VAPOR because it has sulfuric acid in there (a chemical that does not vaporize easily, but it will in fact make corrosive acid gas if it does). Thankfully sulfuric acid does not like to vaporize and it takes a really hot malfunctioning battery to start essentially boiling H2SO4 aqueous into H2SO4 vapor.
If you ever come across a alkaline battery leak, it often sounds like a capacitor pop, followed by intermittent hissing or farting noises after that.