Let's begin with my configuration. I have a 7700x ps2 slim + FMCB + 4 GB USB stick.
Ok, so what I've been doing since getting FMCB is burning unpatched ISOs onto DVD and use FMCB + SwapMagic elf or Cogswap elf to get my backups running. Although this is a viable, as well as the cheapest, solution to run backups. I noticed backups do not load successfully 100% of the time. Also, my PS2 gets picky with the DVDs when loading backups this way. I've tried Verbitam 8x DVD+R, TDK 16x DVD-R, and RiData 8x DVD+R; only Verbitam could read disc without PS2 making lots of noise, RiData was ok, and TDK was plain disaster.
Yesterday, I burned a pathed Jap Front Mission 5 onto TDK DVD as my last attempt with this brand. And...bam.....ESR booted it ...... they way I got it to boot was first setting R1 button to "ESR something DVD off.elf" in FMCB config. Then put in the game, power up ps2, holding R1 button and that's it! I've burned the pathed FM5 onto Verbitam DVD for comparison and my PS2 only made a lil bit more noise reading the TDK one. Video playback from TDK disc was smooth, loading took a bit longer than Verbitam disc occasionally but that's okay with me. Whoo hoo! No more paying extra for $$$ DVD-/+Rs!!!!