Took a while to get the two Z-Uno delivered (got stuck at USPS). First I did not manage to make Vera see the Z-Uno until I noticed the new Frequency setting in the Arduino IDE. Corrected for my region and bingo, works like a charm! Might be good to mention this setting in the Getting Started. In case someone wants to know: One of them will be used to send the graywater tank level alarm - pick up the voltage at the indicator light with an optocoupler, everything directly installed in the alarm box, antenna stuck through a hole in the metal box.
Received as described, sending values to Z-Wave controller without issue. Problems setting up NZRAM and runtime interrupts on Pin 18, but the things that I can figure out work well. Usable as an economical flow sensor.