Like anything, mods can sometimes be influenced by fashion or fad.
Back in the day, all rockers were originally on shafts, then a manufacturer moved to post mounted rockers on their new engines.
Post mounts were new so those who modded their engines modded what they had... in a cost constrained way... as we all do...
Shafts were supposedly more solidly supported but pedistal mounts probably cheaper to make.
So pedestal mounts can flex and high spring force can pull the bolts out, supposedly.. who knows the truth...
It's the same with bearings, originally bronze bushes were widly used and each has it's pro's and cons.
Bushes supposedly have higher parasitic loss but needles through an engine are no fun.
GM even say an oil pump can't suck them up, others say it's not a big issue... yet it's an issue solved by the aftermarket...
Who really knows the truth as there is no one truth.
Even if one has day job designing and engineering combustion engines, you'd also suffer from fassion and fad in your job....
As is, everyone will have a view though it always comes down to money, otherwise we'd all drive ferrari's...
Me, I've always liked the simplicity of a long shaft supporting all the rockers which run on bronze bushes.
Reliable, last forever but maybe don't make highest power in heavily modded engine.
Only thing better IMHO is over head cams with solid buckets (cam followers) but that's a different type of engine.
Either will work well with LS engine.... the issue with the OEM D trunion is fully resolved by a round trunion with circlips but bronze bush will also fully resolve the problem... it's sort of blue pill red pill dilema.
Not helpful i know so i'd talk to HPF as they have done your mods and it's worked well for you so their opinionand what they are more comfortable with will probably be more valuable to you..