If I’m being honest, the lemons in the mash are essentially a substitute for the lactic acid that I would otherwise need to drop my pH in line. Maybe if I squint I can pick them up in the finished beer. Zest at flameout, and maybe dry hop, and maybe packaging, and maybe in the glass, are really needed to get past the yeast, imo.
The whole idea for using lemons in the first place came from a podcast I heard with the owner of Rowley Farmhouse Ales in New Mexico. I emailed him and he got back to me with some tips. Nice guy. My nephew made it there one time and he scored me some beers. He said it was one of his favorite breweries he has ever visited, and he has visited breweries all over the world. Lucky bastard.