Hi the periscope lens is used when there is sufficient light because it use a lower aperture (f/4.0 if I remember correctly) instead of the main lens who use a f/1.8 aperture. The 0.8x toggle is the same as the macro toggle.
in fact by making a report with the log files it made space in the other part of the system. unfortunately it no longer works for me and I find myself for 1 week with 34go in the other part ( sorry for my bad english, my French is far better )
since i've installed 20.11.18 in m'y Mi 10 ultra , i've seen an increase of the other's storage every day. I don't think this is normal since I have already format data once ( that same other storage was almost 50 go !!!!)
I don't know what to do