Ziller, no. We are not going by this again. "You're strong" because his technique of one-shot failed does not mean Boros is 4-A.
You yourself are making a thread to make casual Saitama up to High 6-A. Obviously a character beyond his "casual" would be considered strong for him. There is no way to argue Boros to be 4-A, just there isn't
He didn't recontextualize anything. Orochi was just an idea back then. I'm pretty sure the scale of the fight wasn't even decided, and ended to be High 6-C before it scaled to something near planetary
"Almost a real fight", yet Boros at the end of the fight said it wasn't even a fight, he was holding back a lot, etc. Please...
Bruh, the guidebook himself stated that Boros' attack, which was all his energy left, could only wipe Earth's surface. Please...
Ziller, you're trying your best to wank Boros, I admire that, but please, use that energy to something else. 4-A Boros just isn't right. There is no real proof more than just mental gymnalistics out there.
Even if you assumed Saitama holded back the same with Boros he did with Garou ("It wasn't even a fight", "You weren't even trying"), Garou still collided the punch, meanwhile Boros' attack was destroyed just by making contact with the punch. Please...