Are expansion packs supported?

[failrunner]

If they're supported how do I use them?

[LunaMoo]

If by expansion packs you mean DLC's, then yeah, somebody actually asked about it not long ago:

(08-04-2015 11:35 AM)LunaMoo Wrote:  Place DLC files in the same folder it should be on real psp, usually under PSP/GAME or PSP/SAVEDATA on memstick depending on game will be different, but that's pretty much it.

Just a note that if a dlc requires updated game, you will have to update the iso using psp with cfw either using isotool or just decrypting eboot.bin from the update and patch the iso whatever way you want. Updates are encrypted with keys we don't have, so that can't be done on emulators.