I assume you mean "Is anyone using Polyphone as a synth"?
I have no idea, they can use it for whatever they want to - however they would be well advised to use sound fonts correctly.
In my opinion Fluidsynth is the standard by which other synths should be judged and as far as I can tell it uses modulators in accordance with the sf2 standard.
If there is no binary executable available for your mac you will have to compile it from the source. I have done this myself on occasion but it is not a trivial process even for an experienced programmer. csw900
i use the Coolsoft Virtual Midi Synth, it plays soundfonts as good as my Soundblaster Audigy. dont know if there is a Mac version, but Google will help you find out.
You could try dmidiplayer (drumstick midi player) on Sourceforge. It uses fluidsynth and there is a mac version (.dmg) I have just installed the windows version and it seems OK to me. csw900
Sorry I thought you had said your OS was 10.15 which is Catalina. Your mac must be really ancient - I doubt if you will find any support at all for your version of OSX. I think you need to update your OS or get a newer PC. My personal experience with macs indicates that they are the worst possible choice for working with audio. csw900
