Diversion via ASN-PRR will be done by an extra loco in between them. Suppose a train(Rake-L) reaches ASN and needs reversal, a extra loco will be attached at it's back like LE-Rake-L(L won't be de attached).
After reaching PRR(needs reversal), LE will be de attached from back and the original train can continue it's journey having the same CC again. Hope you got it! It will save a lot of time and is like a single QLR.
LE will be ASN WAM4 or SRC WAP4.