Why when i under 60m or even under 40m fox 3 still getting me?

All missiles, even missiles with primary documentation regarding extremely low engagement altitudes such as CAMM have MP and are all affected equally and set to 60m

The thing about shooting down onto the target is that the missile is still being multipathed, but the target is actually in the way and still gets hit. But they can still miss if the angle is right. To this end, it is possible to loft a missile from low alt, at someone in multipath and get the missile to still hit.

Though it is time for MP to be set on a per missile basis and AMRAAM would at worst be set to 40m, but potentially lower

You forgot about angle gating even if u chaff and notch on terminal phase the missile shuts on seeker off and explodes near the last chaff location it sees (so pretty close)

is maw even useful?

But angle gating isnt multipathing though

in the EFT at least, its quite handy for getting the notch aligned perfectly. Perticuarly useful with the terrible CMs the EFT has

i got the f16i sufa

Which I think is a UV/IR MAWS so less useful for that

guys i did my first secssful notch!!!