Wow, it's been a full month since the last post. During that time I tested the rocks for TDS changes; they were mildly reactive - 30 ppm after 7 days in distilled water. They hadn't been boiled, only rinsed, so it's possible something else was dissolving. The plants were on their way, so no more time for testing until flooding. At worst it will be a neo-only tank.
Also I acquired some non-reactive gravel from Caribsea to serve as the base for mini-mosses.