Infantry Aim Assist and Infantry Aim Assist Slowdown can both be turned down to zero so that they have no effect on your precision aiming.
Controller > Edit Settings > Infantry Control Settings > scroll down a bit and you will see both settings. Click on a setting to adjust it all the way to zero if you want. Then click on the next setting to adjust it to zero if you want.
Aim Assist - 0, Aim Assist Slowdown - 0.
They might be able to, as you say, "have an option that automatically disables aim assist for Sniper scopes or for Zoom levels above 4X, for example."
I would imagine however that this kind of thing would be so far on the back burner that we might see it, say, sometime next year. Or not. Actually, come to think of it, probably never.
