I haven't used pushrod oiling on a KB aluminum block, I do use pushrod oiling on my current S/P 400 block stroker motor with a set of Indy 440-1 heads that have a set of the Jesel paired shaft rocker arms with no oiling from the heads
I bought a set of Comp Cams AMC solid roller lifters for pushrod oiling and a set of Indy spray bar valve covers and used both on that motor for the first couple weekend racing, I was over oiling the top end so I ended up taking one of the spray bar covers off and block the oil line off that went to that head. I raced it 3 more weekends like that and saw no harm on the side with no spray bar oiling and change the other side to pushrod oiling only and haven't look back
I have a set of the original B1 heads back east for freshening right now that came with the Jesel paired shaft rocker arm set up like the 440-1 heads are using so I will probably used the same lifters on it to start with, no spray bar oiling this time Those heads are going on a new KB 4.500 bore size aluminum wedge block (572 C.I.) that I'm hoping I can make close to 900 HP on Oregon 92 octane non ethanol pump swill