Molotovs are useless on modern day armour.
Ever since the effectiveness of molotovs since WW2 and vietnam pretty much all modern armour has measures to counter the flames.
the only effective place for a molotov is in the engine.
In the case of air cooled you wanna drop the molotov at the air intake so the engine sucks in fire (not healthy) or on the grill above the exposed engine bay.
Water cooled youll go for the radiator, as the idea of a radiator is to lose heat, cooking it with some fire can make the engine rather unhappy.
as for damaging the optics all a molotov could really do against them is perhaps stain the visor/melt the wiper blade. its this sort of simple thing that causes damage, e.g. rubber seals melting and such, guns just getting too hot to touch
as for lobbing a molotov against a warrior or a challanger and it exploding in a few minutes

as the devs well know, dosn't happen. Modern units have protection in the engine bays against molotovs and such.
Your only chance is getting the fire somewhere where itll overheath the engine.
Now if there was a specific place we had to lob the molotov and if it burned for long enough itd be awesome if the engine was disabled somehow

not in a way that chucking more and more molotovs will destroy it.
Itd be cool to disable armour with a molotov and see the engineers coming to repair him, ambush them

disable an apc and wait for the crew to escape...
In short the best you're gonna get these days is disabled not destroyed. on an intense battlefield it's the same thing
Would be awesome instead of having instant destruction having the tank very gradually lose its functions due to the heat. Engine, 50.cal, Coax, main gun etc
shame we dont have a heat engine... overheating the weapons after a certaiin period of time.
Molotov cocktails (John Schilling)
EDIT: "molotovs are useless against modern day armour" lol not exactly but its very very very hard to get any real use out of them against some heavy metal.