PRS/NRL adds handling on barricades to the mix while ELR should have no reason at all to look a short barrels ,long ones are superior in both finding ammo that will preform and ES SD for said ammo
Olympic-type sling shooting had a short barrel craze in+ mid 90's , the theory driving it was that an unsupported shooter would benefit from shorter barrel time so shorter barrels would induce fewer shooter errors, and for a while short 19-20in barels were seen on all the competitions
In the end ammo just did not perform as well . Short barrels tended to be magnitudes pickier in regards to ammo they shoot well. So as folk had harder time finding match ammo that could shoot extremely well , short barrels went the way of dodo with sling shooters.
BR folks also do not like to go under 24' , and prefer 26'+ as short barrels besides being more ammo picky are also less responsive to tuner input note BR tuners are near 3x as heavy as EC tuners used on rimfire PRS rifles. While BR is weight-limited so you are not going to see barrels past 0.9 straight, folks actually like 0.875 as the more tunable of the two.BR crowd is also very anal in regards to muzzle threads , they rather have tuners clamped than ever thread the muzzle even with 5/8 or larger diameter threads let alone 1/2
My guess is that in couple of years barrels will be slightly longer ( 22-24 )than today and much skinnier if Tuners become the norm. Also, no MTU or any tappers at all as its just stupid to run a tapered contour on a rimfire. The bore dimension will always slightly mirror the contour and you want your bore straight or tapering down , having a tapered barrel you are opening it up ever so slightly.
And the centerfire-sized tenons (Bergara) go way of Dodo
Calfee reverse taper sporter barrel profile is gaming the bore dimensions with contour