Wait for WU6 where you will be able to re-enable the offscreen scenery caching that was removed in SU5, and see. I doubt going up from 32 GB will do any good though. Today it certainly won’t, I can usually not even get MSFS to use 8 GB of RAM.
I have 48 GB and upgraded for flight sim purposes, but as far as today’s MSFS goes that was a big waste. (I upgraded before the alpha even opened.)
That’s in WU6, September 7th.