You shouldn't have significant flavor issues with Briess extracts if you limit the gravity you get out of the extract to about 50 points. That keeps the sodium at reasonable level...assuming that your brewing water has low sodium.
1 ml per gal of 88% lactic is getting up there, but 'most' tasters wouldn't find that objectionable. However, I know that Supertasters might be able to detect it and possibly object to it. I'm a fan of Berliner Weisse, so I'm not one who would object to minor lactic levels. Others might not be as tolerant.
Thanks, Martin. I'm mashing around 5 lbs minimum and adding the extract late. I assume that the mash would be improved with the acid addition, but maybe I'm someone who can really taste lactic.
I served a keg of pale ale on Saturday, because I just wasn't sure about the wit. But the pale went quick, and I tapped the wit later. The keg of wit floated in record time and people loved it, despite my reservations. Perhaps it's just me...