Sorry for my late reply to this topic Tony.
I recently got back to sim flying again with XP12.
I'm using a Mac Studio M1 Max. It has 32GB Ram, but only a 500GB SSD because I'm mostly using external storage.
XP12 has worked fairly well for me, but as I am new to XP I still have to discover how to either install or access better scenary.
My biggest issues have been using 2 external Lenovo 2k screens. I had a lot flicker and parallel lines on the screen appear.
I spent a lot of time playing with colour profiles, resolution and refresh rate to improve things.
I'm still not totally sure which gfx settings are best for my setup to get the most out of it.
I have enjoyed flying from my local airport in Derry, Northern Ireland though.