You pay for the wing clipping in many ways:
1) Reduced wing area leading to less lift (and hence turning force) for a given control deflection
2) Higher angle of attack required for the same lift/manoeuvre force, leading to increased induced drag for the same lift.
3) Lower aspect ratios cause stronger tip vortices anyway, but OTOH a lower aspect ratio wing has a smoother and more gradual "stall" (probably not relevant to AAMs, as their AR is quite low to start with and their wings/fins are frequently deltas, which inherently enjoy a gentler stall).
The missile designer has to adapt by altering the missile's control-loop functions appropriate to the aerodynamics. Otherwise you get Sidewinder-like behaviour with the weapon oscillating from side to side as the guidance loop wrestles with the suboptimal control system (it was worth it in Sidewinder to keep things simple).
Ultimately it's a question of ENERGY - if the missile is still in boost phase, the motor is still supplying the energy and the drag caused by the loss of wing area etc. might slow the missile down a bit but usually the speed differential is so high in the first place that this doesn't matter. If it's in coast phase, that's a different matter - a target which becomes aware of the missile might evade by turning away and taking evasive action in a full-thrust climb, to force the missile to "stretch its legs" and waste kinetic energy trying to follow. At extreme range, this can lead to the missile falling away or failing to catch up.
That being said, there are too many variables. If it's a snap-up or co-altitude shot with the missile in coast phase, the evading target has an energy advantage in the climb (possibly its only advantage). If the missile was following an up-and-over trajectory, it still has height to trade for speed and manoeuvre energy and the evading pilot might as well reach for the eject handle.