When you add acid, it consumes alkalinity. That creates CO2 which makes the pH lower in the water. Then outgassing of the CO2 (from aeration, not the SWCG) makes the pH rise.
Well my SWG produces hydrogen bubbles which provide some aeration I'd imagine (probably not a significant amount) especially compared to just wind. That said, I expected the acid to bring the alkalinity down immediately, and I'm not seeing that (pH is going down immediately). It seems from the Pool School article and other posts that this takes multiple cycles of ph Down + aeration + pH Down + aeration. Not understanding the chemistry, is the consumption of alkalinity a slower process, it must be to support those statements.