In return, I fully agree with you, adding lactic acid (or any other acid) to a beer is definitely the wrong way to create sours, but in small quantities some subtle acidification through a lactic or phosphoric acid addition, is fine, as long as you can't really taste it. Phosphoric acid is more neutral to our palate, so larger quantities may be used before its flavor becomes detectable. Now more is generally not better, since we want a subtle change to perk the taste buds. A good high carbonation serves a similar purpose.
Other than for genuine pH correction, I don't see why adding those small amounts of acid to a bottling bucket would be any different than adding it to a primary or secondary, except, if the pH drops too low in a fermentor, yeast activity and behavior will suffer. Hence I suggested adding it later.
No, I've not had the need or urge to add acid before packaging.
But I do add some to mash and sparge waters to obtain correct pH, and nothing beyond that.
I now start to wonder where the various acid/pH levels lie with extract brews. I've never measured those in the past...
+1 on the Belle Saison. And it gets better with subsequent use, so @CaptBrew8386, harvest some for your next batch.