No emulator is perfect, and i'm sure people have dropped SNES emulation developement on PSP long time ago. I mean maybe not dropped, but pretty sure with in the last 6 years since 2011. 3DS and psp aren't even the same generation systems, and is completly unfair to comapre something meant to be play those kinds of things than something not meant to play them, not to mention how the age difference is. Longer aged consoles had longer time for homebrew development to get better while younger does not, which isn't fair to expect it to be good or better.
I just have a curious question, do you have a psp 1000? If you are using any of the others, i think you may have to finid the high memory mode extend version of the emulators. Some emulators were made to take advantage of the extra ram that they added to the psp models after 1000 so it may help, also set processing speed to highest, (Recovery menu, game processing speed 333MHZ) I dunno if it will help but other than that, you will have to manually configure settings for each game as needed, including speed hacks and other misc. stuff. Is all i can offer, unless there is a more recent emulator.
As reminder, Most mobile/console emulation isn't as good, or either can be better but just dropped supporting developement.