lenses

I assume that the native lens is used when setting 0.5, 1.0 and 2.0. And the digital magnification is added for such settings as 0.7, 1.4,, 6X. Is the correct and do you have any comments about that I'm moderately experienced with photography, but a novice with the iphone 11 pro. Is there a...

I'm considering purchasing an external lens kit for my iPhone to help improve the quality of my pictures and video, but first I'd like to get your opinion. Are they useful? Do they make big different in terms of quality? Can you get nice bokeh with them? Stuff like that.