Your question also makes me wonder if he's using an HDMI switcher or AVR or device in-between the MIO and the tv set that's flaky in some odd way.The North America Project image only supports North American standards and doesnt need a "patch" for operating with North American TVs only compatible with 60hz refresh. TNAP only offers 60hz refresh and only resolutions supported by NA TVs. There is nothing in the TNAP wizard that could set to any 50hz or a resolution not supported by NA TVs.
The SatDreamGR image is different and it offers all 50hz & 60hz refresh and resolution settings.
There is something else going on. What resolution is your TV set to? Did you connect with the new HDMI 2.0 cable that you ordered? What is the maximum resolution that your TV supports?
If so, and if he hasn't already tried, he needs to connect the MIO directly to the HDMI port on his plasma to finish setup, and then go from there to figure the 'why' beyond that.