From my testing, 1.5.4. works completely fine. Just as well as 1.4.2. In fact the current ng+ record was done on 1.5.4, so go ahead my guy. if you ever have any questions about the run or emulator question, feel free to hit up the ratchet and clank community discord or continue the questions here :>

I've used PPSSPP 1.5.4 and, honestly, there doesn't appear to be any difference between 1.5.4 and 1.4.2. As Weez has stated, I'm sure you can just go ahead and use that one :)