You might want to use a little acidulated malt to get the mash pH closer to the ~5.3 desired. Gose tends to be a very pale beer without a ton of specialty malts, so without the acidulated, your mash pH might be high at like 5.8-6.0, so you'll likely find that a little acidulated malt is a great idea for pH control, even more than it is for flavor contribution. Otherwise I'd agree, a bit of lactic acid added after the mash is done would be okay to add the desired tartness in flavor. Or better yet, go the route of a sour mash or partial sour Lacto fermentation or whatever, and don't add any acid at all.
Anyway........ the one authentic imported gose from Germany that I tasted was not very tart or salty at all. It was more like a witbier than anything else. I get the feeling that everyone in America just loves to overdo everything. So, consider whether maybe you don't need to bother with anything too fancy, yet it might turn out even more authentic in the end.