In reality, there isn't really any need for PSF support specifically. They're basically just compressed EXE files, so if an emulator supports loading bare EXE files, you can just convert the PSF to EXE using e.g. psf2exe. And should it not support that, you can build a completely valid PS1 disc with e.g. mkpsxiso. Sure it's not as convenient, but it can be done.