Re: Gewürztraminer

The main con I can think of is that acid blend contains malic acid. If the wine has already finished ML, adding acid blend may very well start that going again.

Best to stick to tartaric, and get that in as close to the start of fermentation as you can. Adding tartaric late can cause cold instability in the wine.

If adjusting just before bottling, citric acid may be best.

Tom S