Without wishing to teach any grannies out there to suck eggs the weight at which a SHAR can hover (and so do a VL) is NOT a simple number that depends only on ambient conditions and the particular performance characteristics of the specific engine in your jet. There is another issue and that is engine life useage. If you choose to turn off the normal temperature limiting devices (a cockpit switch in front of the throttle box) you can SAFELY run the engine to higher temps and so greater thrusts than with the limiters ON.
By safely I mean it will not surge and it will not fail mechanically. But it will cause the engine life recorder to run up a bunch of counts which will mean you to need to replace the engine earlier - how much earlier depends on how much hotter and for how long blah blah blah.
So to say that it simply can’t be used to ring back expensive unused AMRAAMS in high ambients is a bit of an oversimplification. To put it mildly.
Mulled wine anyone?