I did the following procedure for my NTSC-U Wii + 1.9g and ended up with a normal Wii, no duplicated channels.
0. Update Wii to latest version through online.
1. Patch the ISO with RegionFrii.
2. Burn the ISO at 2x with IMGBurn and verify turned on.
3. Patch the
SAME ISO with Brickblocker (so now it's RegionFriied AND Brickblocked)
4. Burn the second ISO at 2x with IMGBurn and verify turned on.
5. Pop in the first burned disc.
6. Update to ~10-15%, pull the plug.
7. Pop in the second burned disc.
8. Works perfectly.
9. Throw away first disc, it's useless now.
What's the point of using RegionFrii if you have the Wiikey? I thought it could already play other regions... but hey if this seriously works perfectly without risk, then I'll have to try it. By the way, does it tell you the percentage as it updates or do you have to carefully eye it out?
Edit: In RegionFrii you set it to USA if you have an ntsc-u system and a Jap iso, right?
Also, is Sonic unlockable on this dump?
There's a chance that the update to support DL is actually added at the end of the update, 15% would therefore stop that part being installed and stop the original or a DL copy playing.