OK, First go on over to kit guitar forum or the OLF and search water based lacquers. And search here too, I've posted on them, and a lot of good stuff on the other boards. Hate to plug the other sites, but that's where the info is.
Second, I have no experience with Stew Mac's product, but I use Target coatings EM-6000, which is a replacement for Their USL, which is what Stew Mac relabels and sells.
Third, you can brush water based lacquer. But, you don't THIN it. You need to add RETARDER, 15-20% by volume.
It, does burn in so no witness lines.
You want to use a very fine bristled brush, and put on very thin coats to keep brush marks to a minimum. I recomend the Davinci brushes Target sells in their website. I found that NOT loading the brush helps get a smoother coat. And keep the brush nearly perpendicular to the surface to avoid bubbles.
I like to put on @ 6 coats then level, then @ 6 more level again, and if I get no sand through, I'll put on 3 more, let cure a week, level, micro mesh to 2000, then hand buff with Mequirs products.
You can even use TransTint or Mixol pigments to create toners and shaders, although you don't need retarded if you use pigments. Make sure you get the ones for Waterbased.