I have used it on PC VR before, in fact bullet train used POM a little bit. In the tunnel one of the yellow floor tiles had POM. It used to be in the main combat area but was changed for art reasons. You just have to use very few steps and make sure you profile.
for mobile I would be surprised but it may work if your scene is carefully budgeted and you keep the number of steps low (ie less then 8 or 16 or something). as an example, the recent samsung galaxy epic demo had some raytraced metaballs in the intro and that shader was similar to POM in complexity but it had to be tweaked to run fast.