bertsirkin, have you used or know anyone that uses a telephoto or wide angle lens attachment for their Note 4? I have shot through the eye piece of my f10 2000mm SCT using a 18mm wide field eyepiece with quite good results. At just over 110X magnification, terrestrial observing is a bit challenging. I could probably use a .67 focal reducer and field flattener to get down to just over 50X but would like to use a adapted zoom lens from one of my SLRs instead. I have also shot using the Note 4 through some of my stereo microscope eyepieces but image crop down to about 30% is typical. It is a bit off topic, but thought I would ask you about it.
You are right that really does not make any sense to put a variable aperture in a 4.8mm lens.