don't use the word "USB" (connector type) to talk about "flashdrive" (device type).
because HDD (external hard disc drive, with rotating magnetic plates) are also using USB connector type !
this is USB
This is flash drive, pendrive, USB stick, USB key, whatever you want to call it, don't give it "usb" name only.
These ARE NOT WORKING correctly.
This is external HDD, what you want for Wii and vWii and WiiU:
if it's too expansive :
don't by 8TB ! just find a 250GB instead
don't by lot of random 32GB flashdrive which will not work, you'll waste your money more than buying ONE working HDD.
If you can boot inside CFGLoader, you might not be able to play any game, so no, it's not working.
if you can read content, you can't write (dump disc, download covers, etc.) so no it's not working correctly.
If you want to change a setting in USBLoaderGX to be like other loaders, go to settings>loader's settings. Change "loader's IOS" from 249 to 58.
but like I said, it'll fake that it works, but you'll notice that it doesn't.
SD Card can't be used to play Wii games with USBLoaderGX, you'll need CFGLoader or wiiflow, and you need to know that some games don't work on SD but work fine on USB (kirby for example).