Well so you plan on flying IFR and details will not make very big difference.
Depending on you screen resolution you’ll want to get the more FPS possible sacrificing details as you won’t be doing vfr.
If you are on a 2k monitor recommend to put all on high and the render to around 50%. You won’t notice much difference and you’ll get stable FPS.
If you are on a full hd monitor , all on high and 80/100 render would be good.
My advice to you is forget about New York “benchmark” . Go into KLAX airport and depart from there with above settings and check your best scenario.
To see the FPS counter you need to activate the developer mode (options menu).
It’s me know how it goes and keep up the spirit!