I'm glad it is useful to some peoples. I sure wished somebody had done it before me!
I tested over 40 games using mapper #206. Most were incorrectly assigned mapper #4. Most of them would not work properly on mapper #4 so I fixed the header of those specific game. Some seemed to work properly even on mapper #4 so for now I'm not going to add them to my No-Intro fix pack. Some surprisingly were working with the incorrect mapper assigned and wouldn't with the proper mapper #206. I find it very curious and will try to find the reason for this (different undocumented revision maybe) but I obviously didn't change anything for those specific games as to not break compatibility. I updated the fix pack for the No-Intro set and the following game are now playable:
Babel no Tou (Japan) (Incorrect mapper, mapper #4 instead of #206)
Family Jockey (Japan) (Incorrect mapper, mapper #4 instead of #206)
Family Mahjong (Japan) (Incorrect mapper, mapper #4 instead of #206)
Family Pinball (Japan) (Incorrect mapper, mapper #4 instead of #206)
Side Pocket (Japan) (Incorrect mapper, mapper #4 instead of #206)
Super Chinese (Japan) (Incorrect mapper, mapper #4 instead of #206)
Super Xevious - Gump no Nazo (Japan) (Incorrect mapper, mapper #4 instead of #206)
Valkyrie no Bouken - Toki no Kagi Densetsu (Japan) (Incorrect mapper, mapper #4 instead of #206)
I also decided to switch to BPM patching instead using the aging IPS format. It is now possible to patch all the games at once to save time. You can still individually patch them also if you prefer to only patch what you plan on playing with.
New No-Intro fix pack