Good to know. I knew about the asm hacks though.
I know that the slowdown isn't as bad on newer PSPs - ones with more RAM, or clocked faster? I'm reminded of the appalling slowdown on the PS1 ports of FF4, 5, 6, and Chrono Trigger. Asking the guys at RHDN about the slowdown on those games could yield some clues, along with finding out if UMDs read slower than CDs.
Don't you just need to unpack the files, find the data and edit it in a Hex editor?The game crashes or freezes, or any other issue when you try to apply an ASM hack to the PSP version.