cIOS38 rev 17 is the same as cIOSx rev 19 except 19 is an updated revision. This is used for USB Loading and not just disk loading. That is why what you said makes no sense.but without installing cIOS 38 (My Wii can't do disc backups, so there's no point),
Your other statement is only partly true if you have a modchip installed as 4.2 disables out of region gaming with modchips ONLY.
My advice is to listen to the mods. Take it or leave it. Cheers.