In theory, with parametric design (eg OpenSCAD, Autodesk Inventor, etc) a model could allow you to enter the phone dimensions and it automatically re-calculates the correct geometry.

In practice, experience says doing this (in a robust way) is a lot harder than it sounds. ;)

Thanks, very nice design and write-up.

I wonder if there's a version that's more of a shelf so could accommodate (m)any sized phones and with/without cases?