Awesome, I see a lot of progress around here with 60 FPS cheats.
I have a question, how are you checking that you have changed the internal FPS of a game? I mean, PCSX2 doesn't have an internal FPS counter (like PPSSPP), and even when the change should be evident to the eye most of the times, PCSX2 needs more hardware resources than other emulators and some games are just to hard to run at full speed for me (or for everyone with games like Metal Gear Solid).
Some weeks ago I posted
THIS on the github issue about the internal FPS counter. It's a crazy workaround to know the internal FPS of emulated games, but with all the games I've tested it works.
Also, I asked a question there and I'll ask again here in case someone know the answer: if there is any way to get the internal time of the emulated PS2? Maybe using a generic syscall or something.
Why I ask? For PSP, sceKernelGetSystemTimeWide function returns the system time as an int64, with every 1,000,000 being one INTERNAL second on the emulated game. Using this function and some generic assembly code, I can inject it on any game and run it once every frame and get the time difference between every rendered frame: if the game is internally running at 30FPS, the difference between the previous returned value of that function and the actual value will be around ~33,333, why? With some calculations: 33333/1000000=0.033333, and 1/0.033333=30.0 FPS
For PPSSPP this is not that useful because it already shows the internal FPS, I have used it to dynamically calculate gamespeed for fixed gamespeed games. But for PS2 games this would be a perfect way to get that needed counter.
As a recommendation, you should check PS2 games with PSP versions or similar/same engines, if their PSP versions have a good working cheat, the same approach should be possible with the PS2 version. Marvel games, GTA stories and pretty much any first party game are good examples. Learning from what has already been done before (or similar) should help with PS2 exclusive games.
In case it's useful, I have posted a 60FPS master list with all the known released cheats for PSP games, just go to the FPS discussion thread at the PPSSPP forum.