latest DEX multiman question and DEX firmware

I just successfully converted to dex, and i dont want to go through all the hassle to play backup games on my DEX 4.21, so my question is,

can i play backups of old games on my DEX 4.21 using the latest multiman DEX? i tried booting multiman but it exits to xmb with an error.

is it possible to simply use multiman DEX without going through all the mounting and ps3gen stuff to play backups?