OK, i'll try to help you understand =P
With the New cios Rev15 they Set one of the IOSs to place DL/DVDs and Newer games BUT in doing that it Cut off Other games from working =( So i still stay with Cios Rev14 =)
Right now when i Hack a New Wii System I do this
1. use the bannaer Bomb hack
1.5. If need be i do the Trucha Bug Restorer
2.Install wads (all in what version they are) with 3.0 to 3.2 just install from WAD manager with
3.5-4.2 you Need to switch back and forth from Custom WM and WAD manager installing the Wads till all install on WAD manager.
IOS16-64-v257.wad
IOS36-64-v3094.wad (for some reason in my pack this is on the root Not WAD folder LOL)
IOS38-64-v3610.wad
IOS50-64-v4889.wad
IOS53-64-v5149.wad
IOS53-64-v5406.wad
IOS55-64-v5149.wad
NeoGammaR7.wad
(3.5-4.2 May need cios_fix.wad) for Cios Rev install.
I even install the IOS15-64-v257.wad and IOS15-64-v266.wad from WAD Manager BUT!!! you don't have to LOL they are not for WAD Manager install, I just installed them Once by mistake =P
3.5. Install preloader v0.29 With a Good Hacks.ini file set for the Version wii.
4. then i install Cios Rev 14 and cIOSCORP_v3.3 (witch installs like 23 IOSs LOL (don't install this on a Wii 3.5-4.2) You will need to downgrade to 3.2 before Installing Cios corp.
(you can Install cios corp on wii's versions 3.5-4.2 BUT some Errors Made happen Like a Upside down HBC LOL
5. By now a good 99% of all games should work =P After that i do the GH5 fix and more or less done
(Note Not all games can run from Disc channel But a good 98% of games will work from Disc channel)
6. you may want to install CMIOS as well for CameCube games. Oyea and Maybe DVDx

7. And now with the New Mario game i'll install IOS53-64-v5406.wad But still need a patched version of the game and does not load from disc channel Only NeoGamma R7
SIDE NOTES.
I do have the OLD IOS36-64-v1042.wad that i use some times to help in the Installing of the WADs for Newer systems like 4.0-4.2 as what i do is use Custom WM then Install IOS36-64-v1042.wad and Cios-fix then do the CIos Rev Install (makes it a little easier on me LOL)
Sorry if this was a LONG read LOL i was just trying to get ALL the Info out there that I do to get all the games working on a Stock Wii to Hacked Wii. I some times use Firmware-Updater_4.1 to get a Wii at best on 4.1 for them If they want that So they can use SDHC cards. But I still say 3.2 is Best. My friend Was on 3.2 with all installed then When the New Super Mario came out he used the patched version and just did a System update So now he is on 4.2 LOL but all burned games work SO.. All good LOL.
Ps...
Some times Wii's can Be a *female dog* and Not work in the say way as the other Wii's So with IOS Installs you Just go to play around till they install BUT just be carefull and NEVER Unstall a WAD HAHAHA
AND.... maybe Install HackMii and backup Nand =p so if you do brick you can fix it. I have bricked 2 wii's BUT they where my own retard fault (good thing i had preloader Installed LOL)