I know the 7M’s stated min altitude is 5m. This was achieved via a mix of a new seeker, a new “smart” fuse, and a new directional warhead, though thats not really relevant for low alt intercepts, it just makes the missile more lethal). I made a bug report about this and its been acknowledged, but not been acted on. The fact it can guide on PD signal likely helps as well, though I’m not 100% sure of that.
The skyflash is also highly resistant to MP, as is the R-27ER allegedly (though I’ve heard competing claims).
AIM-54A and C use PD seekers, and the 54C specifically has a whole new digital seeker, which, though we don’t have exact numbers on performance, was stated to great improve accuracy in high clutter environments. Particularly to combat very low altitude waves of sea skimming AShM’s. (Gaijin pretends the 54A and 54C have the exact same seeker in-game though, making the 54C effectively worse in every way). The 54C also uses a new “smart” fuse and directional warhead, though if I understand correctly, its fuse is directly related to the radar itself.
All the new ARH’s should also be highly resistant to MP.
Gaijins already stated they model multipath the way they do as a “balancing factor”. Imo this is shortsighted and stupid as a balancing factor since 1. thats what BR’s are for and 2. it unfairly sways missile performance for S/ARH’s towards pure kinematics performance instead of seeker performance, which makes the 7F better than the skyflash for example despite not really being the case irl (the 7F’s seeker was inaccurate, its why it got a bigger warhead, so it could afford to miss a bit more) or the R-27ER better than everything, particularly when gaijin’s other game modeling features greatly favor eastern missiles, such as missile diamonds no matter what if the missiles motor is burning, which is an advantage for short burn high thrust missiles (seemingly the eastern missile doctrine) and a disadvantage for long burn and/or low smoke motors (oddly mostly western missiles).
Excessive multipath is also a major disadvantage for planes with advanced sensors and good S/ARH missiles but poorer performance, such as the Tornado, or the MiG-29SMT, by allowing all other jets inferior at long range combat a “get out of jail free” card where they can close the range no matter what you try to do because multipath will handhold them to the merge.
IMO, excessive multipath in WT is the single worst thing to have ever happened to top tier air RB, and the game cant really move forward into the modern jet era properly without reworking the mechanic.
As some people have said, the new ARH missiles likely wont change much if multipath is kept to the excessive level currently seen, since you will always have a way to avoid them with 0 skill required. If anything, they will actually reinforce the terrible low altitude multipath furball garbage that is the current “meta”, because the game punishes players who bother learning radar missile combat by offering the single biggest in-game crutch to all players who couldnt be bothered to learn.