Overall, this goes into a topic that I find interesting. Whenever the PL-15 is brought up and how the USAF was in a situation where it lost it's edge, people always go to the range discussion. I find it interesting because if the USAF was solely interested in closing the range gap (as some phrase it), then making use of the space freed up from shrinking electronics when going from AIM-120C7 to D3 would have made the most sense (immediately that is). Instead the USAF went the long route and went with an entirely new missile, probably because they were after more than just range.
It's also interesting to see the AIM-174A, which budget documents seem to indicated likely kicked off in or arOund 2018. But still took quite sometime to reach a point where they had a few hundred missiles (as has been confirmed to me). I wonder if the USAF looked at adapting something like the AMRAAM-ER (with ESSM motor) and decided it would have taken just as long as fielding a new missile.