Pretty impressive work.
Sounds like if you have FreeMcBoot, it's slightly redundant. (You'd still have to use the same ESR patcher for backups, just have to modify some stuff differently.)
But it obviously works wonders if you want to play backups, homebrew, or w/e without having to resort to Swap Disk/FreeMcBoot/etc, which is pretty great.
Doesn't everyone just use FreeMcBoot w/Open PS2 Loader on a large PS2 with a network adapter and an IDE-SATA converter at this point? Might as well be an ODE, and SATA drives can be huge compared to SD cards.
Apparently OPL has come a long way and you can use a Slim PS2 and SMB loading to play games off your local network via a local networked PC which transmits it to the PS2.
(You could use USB loading too, but it'd be much slower since it's using USB 1.1 speeds...)
It's been well over a decade since I've looked into this kinda stuff, and it's impressive how far it's come since.
Holy shit! No need for swap tricks? What about PS1 games?
IIRC, this is possible, but you gotta jump through a few more hoops to pull it off. (And even then, I don't think it's perfect.)