Do you know what is the main performance cost for your game? I'm getting 5 fps on my mac. And have you ever tested fracturing Godot on mobile before?
I have only tested the game on 2 or 3 systems and all of them are windows, so I can not really tell you much about the performance on a mac. But I tested it on my laptop and it seemed to run fine there. 5 fps of course is not an acceptable framerate... The fracturing polygon tool for Godot is not yet used in this project but it is used on another game of mine called Fracture Hell, so you could test the performance there as well.