1. cIOS doesn't change anything for DIOS MIOS.
the cIOS is only used by USB Loader GX to see the content of the drive in order to select which "game name" you want DIOS MIOS to launch. it's not USB Loader GX which is launching the game, it's DIOS MIOS.
port0 is read by all cIOS
port1 is read only by hermes cIOS and d2x v9+
When you select a game, USBLoader GX tell DIOS MIOS which game you want to play, and Exit. all cIOS are unload from memory, and the console reboots (no IOS are loaded, so cIOS doesn't matter anymore)
the Wii launch the MIOS (which is DIOS MIOS), and DIOS MIOS works with both ports.
It checks first if there's a drive in slot0, if nothing is detected after 10 seconds it tried port1.
Best solution: use port0 (the bottom port, the one nearest to the edge).
Once DIOS MIOS find a drive, it search if the game you want to play is on the drive and load it.
-> At this moment it show the splash screen.
2.
Video mode "Force console default" is not always good.
GameCube video mode need the match the region of the Game.
If you are on a PAL wii 576i, playing a NTSC game (480i/480p), and you "force console default" then it will force PAL 576i.
But the game need NTSC 480i/480p, you will have wrong colors if you set 60Hz, and the game will lag (bad refresh rate).
Best mode is "Force game default" to always match the game region.
But, DIOS MIOS (Lite) should detect the video mode automatically (if you are using the correct USB Loader GX revision, as I changed many times the way video modes are working).
DML Video mode : "DML Auto" is the best option. it's setting the Wii to the detected "Game Region".
You can use "Use game Setting", which allow you to select the video mode manually, but again if you set "Game default" is exactly the same way than using "DML auto".
Forcing the Game setting video is when you want to force PAL on a NTSC game, or NTSC on a PAL game, or PAL480, etc.
using "Force Game default" should be un-useful with DM(L), and USB Loader GX 1201 mod9+ (sorry, r1202 will be released soon).
The "DML AUTO" is checking both the game region and the Wii setting.
"AUTO" check the game region, if it's PAL it's using PAL settings.
Then it checks the Wii settings. PAL wii have 3 settings: 50Hz (576i), 60Hz (480i), progressive (480p)
If you are in PAL 50Hz in wii setting, it will set DM(L) in 50Hz! don't try to enable 60Hz in game selection menu, it will only ends in wrong colors.
You need to set your Wii setting correctly, the USB loader is not enough.
OR
you need to set "DML Video mode" to "Use game setting" and force a video mode manually.
3.
Some games don't work when compressed or altered.
You should always start testing the game with a 1:1 ISO.
Best settings in USBLoader GX:
HDD menu:
GC install compressed: OFF
GC installed Aligned: OFF
Global Loader menu:
Gamecube mode: MIOS (original and custom)
DML Video Mode : Auto
DML xxxxxxx : OFF for every other settings
DML Force 16:9 : ON (it's your own choice, but I like it ON. Just remember that some games don't like that setting and you need to disable it. I put it ON by default because all the games I'm playing are working with it. I tested them with OFF first! But instead of setting "ON" one by one in all indivifual setting, I'm setting it ON in the global.
Individual game setting:
Nothing to change!
Except if you want to set "DML Force 16:9" to OFF.
First try the game with all default settings.
If the game works, you can try to force the game to run in 480p.
DML Progressive Path: ON
If the game works in Progressive and 16:9, good for you
If the game freeze on a green or black screen, but the game is playing (you can push buttons, hear music, etc. just no visual), then it's a video mode problem.
What is the config of your Wii?
The "DML AUTO" is checking both the game region and the Wii setting.
if you are on a PAL Wii, set to 50Hz, then the USB loader will set DIOS MIOS (Lite) in 50Hz!
If inside the game you choose "60Hz", it will not work fine.
If the game is ONLY 60Hz (Metroid prime), it will not work either.
You need to set the Wii video setting correctly or force the correct video mode.