I'm using flash sticks, and 2 of the 3 aren't detected by the USB Loader if they are connected to the Wii before launching the Loader, but they are detected inmediatly when connected after loading the USB loader (Ultimate V7.4).
I think that might be a problem with the state in which the Wii is...
I may try the new ram site, and download more RAM to my Switch. Not sure if ddr3 is the right ram
for it tho. Edit- no it uses floppy Ram, just like @AncientBoi