How do “Aim assist window size” , “aim ease in” , “aim smoothing” , and “dualzone/exponential ramp or linear ramp” affect gameplay, and is there some sort of “meta” on these controller settings?
Just buy xim apex or reasnow S1 
No idea what are those
Disable them and use switch motion controls instead
Cannot be disabled afaik. Can u disable PC control settings?
Aim assist window size - Determines the size of the window before the aim assist kicks in, the lower it is the smaller the window (For instance on low window your assist doesn’t kick in until the retical dot is on them.
Aim ease in - Effects your dual zone, linear, exponential. the higher it is the stronger your aim will slow down when you are barely moving your analogs. Used for more precise aiming.
Dual Zone - Goes slow when slowly moving the analong, goes to max settings faster for when analogs are flicked for quicker turns. Really helpful if you play high settings but still want that precise aim (Doomfist, Genji, Tracer, McCree)
Exponential - Don’t understand the point of this, never used it and don’t recommend it
Linear Ramp - Keeps everything at same speeds (for turning and flicking). It is decent for people with high aim assist and low settings. Will get you killed dueling a tracer.