There's no setting to speed up how Unreal imports assets aside from updating your CPU - this isn't a fault of Bridge, this is simply how Unreal imports assets.
I am using quixel megascans through bridge on my iMac, 4.2 GHz Intel Core i7 with 40 GB RAM, and it takes forever to load things into UE4. Is there some sort of setting I can use to speed things up?