If it's an IR seeker, the cooling might be able to prevent damage, but is it enough to prevent heating the seeker sufficiently to cause the missile to lose lock

If it's an IR seeker, the cooling might be able to prevent damage, but is it enough to prevent heating the seeker sufficiently to cause the missile to lose lock? What happens if the laser turns off/loses track at 2 km while dropping flares - can your missile differentiate between flares and the skin of a plane in that scenario? And I can't help but think that a pinpoint source coming from your target is harder to ignore than one coming from anywhere else. Either way, at mach 4 it takes ~3.5 seconds to cover 5km. 50kw * 3.5s = 175kj, 42 grams of TNT equivalent. That's still a fair bit to mitigate. (but also not nearly as much as I was thinking)