I have been using the newly created Multi ISO DVD5 =D
I'll gladly check the controller bug with the original GC disks, lemme check, i'll edit this post in some minutes.
EDIT: Funny, it does not happen with the original disk (RE2/RE3). Haven't tested with a RE2/RE3 single-game DVD-R, but so far it only happens with the MultiDVD5.
There's some weird issues with the Multi-ISO code that causes it to "mostly" work, but it breaks randomly. I'm not sure why. (The same issues were present when I tested a DVD5 with the regular version of Nintendont.)
Anyways, I just tested Memcard Multi, and aside from it taking a while to create the blank memory card image (which I'll look into now that I finally reproduced it), it did shut down after starting the kernel. Going to try to figure out why.
EDIT: Well, that was quick. When I updated Nintendont to use the BI2.bin region code instead of the Game ID, I accidentally removed ".raw" from the filenames for Memcard Multi, so it tried looking for "ninmem". Since that file doesn't exist, it shut down. Oops. :V
EDIT 2: Seems f_expand() made it a bit slower than normal, but it's still slow even without it. I increased the write size to 64 KB (up from 32 KB; it was originally allocating a full card's worth of memory, which caused issues in some cases), and added a progress screen. It seems to be slow on the first and second 64 KB writes, but fast afterwards.
I'll probably release another test build tomorrow after merging in the Triforce Arcade Mode changes.