That would be a cutie!
I myself really don't like Sphagnum, things go eventually downhill for me if I use it. I would think your watering practices might decide if you mount the plant or pot? I myself would probably prefer mounted because I water daily.
I also like Coconut fiber a lot. That is the stuff you can buy in mats, and the perennial baskets are lined with it. I soak it and pull it apart a bit and use it the way one might use Sphagnum.
Anyone else?