Irisman, and the ability to Exchange PSX Discs

I been doing a little research, because I am looking for a means of playing PSX ISOs on a PS3. Now I've already modded the Super Slim with HEN, and used Multiman and Irisman. I learned that Irisman can possibly exchange discs with a button code pressing. Yet I have looked around, and haven't yet found any instructions on how to do it, when you need to change discs for a PSX multi-disc game, like Metal Gear Solid.

So I am wondering, am I missing something? Do I need to name the Bin/Cue files...

Irisman, and the ability to Exchange PSX Discs