Adjustable phone stand

I really liked the tablet stand
https://www.thingiverse.com/thing:4781533
It is simple, concise and perfect in its simplicity. No support required.

However, when it was printed, the star of the castle constantly deteriorated. As a result, I found an error in the original model - a gap in a fraction of a millimeter.
Of course, you can set up the slicer for gluing such small cavities, but I was offended for a good idea, ruined during execution.
I wrote to the author, but he did not understand me, or ignored me. (Later the author corrected the model!)
So I decided to draw the same stand myself.
In the process of modeling, I came up with a lot of ideas, I tried them, and after three weeks and a dozen attempts I finally settled on this one. It turned out to be much more complex, but functional.
2021.05.23: added a subtle option, suitable for PETG and PLA