Incredible mod. I would have never thought anything like this is possible in IL-2, let alone coming from modding community! A big hats off to all involved.
I have some suggestions I'd like to share though, with an intention of perfecting this mod even further.
1. The target that's chosen by a missile is the one which has the higher power output, consequently emitting most heat. This is a very good way of choosing a target the missile will attack, but there's room for improvement. Heat seeker in a head of heat seeking missile will lock on the target, which the missile receives the highest heat flux from - the most Watts per square meter. Now heat flux falls with a square of distance (just like a light flux etc.), which means that if you have two identical planes ahead of you with exactly the same throttle setting, one at 1km and the other one at 2km ahead of you, the closer one will give you 4 times higher heat footprint. Probability of missile locking on the closer target should in this case be much higher than the probability of it locking on the farther plane. Or, different example, if you have a heat source at 1km and another one which has double power output at 2km, the closer one will still give you two times stronger IR signal despite the source itself being weaker, simply because it's closer. Bottom line - in the "locking on algorithm", the missile now chooses the highest P (for Power). It should choose the highest P/(r*r), I believe this correction shouldn't be too hard to implement.
2. I really like how the rear-aspect of this missile is done. It's nearly impossible to lock on from any other angle apart from 6 oclock. But this should however only go for jet aircraft, which are a very strong IR emitters into the rear hemisphere. Piston driven aircraft emit the heat much more isotropicaly and should consequently be harder to lock on, but on the other hand the probability of locking on from rear shouldn't be much higher than the probability of locking on from any other angle, if at all. BUT - the missile will much easier hit from the rear than from any other angle, despite being locked on, due to less maneouvering and easier target (no deflection).
Guys, I really like this mod and again I can't express how amazed I am. Being a big fan of early cold war scenarios, I'd only like to contribute to this area of modding, but unfortunately I'm a complete java iliterate. Please consider this post only as a suggestion on how to further improve this masterpiece - no criticism intended at all.