Here is what I know on Magic John/Totally rad, from Moosman's page:

http://playoffline.wordpress.com/mod/rgbppu/



Comparison between composite and RGB shows the background is the wrong color.. perhaps Magic John is immune from this effect. Fully playable either way.

On the subject of getting the powerpak working in RGB yes it is required to replace one of the chips on the motherboard of the Famicom or NES. acem77 figured it out and posted his results here a while back:

http://nesdev.parodius.com/bbs/viewt...er=asc&start=0

The same fix is on my NES deck and it works like a champ, there is a poster who tried it on a Famicom and seemed to have a good result too. A good thing too because the FDS compatibility provided by the Powerpak's FPGA makes it so I can store my FDS collection and play them with ease.

The multi output on my deck is due to the RGB out being piped into a JROK 4.1 encoder board. I've seen a few of these put/modded into plastic shells so its certainly possible to do it externally, but it is initially sold as a bare pcb.