I've designed
this universal phone-holder for the Fanatec-bases and SimuCube as well, but never thought anybody would want some bigger screen blocking the view to the display and if it's not blocking it, the FOV is wrong. I've also made a version for tablets, but for fixing it to aluminium profiles below, above or at the side of your screen(s) with adjustable joint-connectors. From my personal use I find anything larger than 6" is just useful for larger position-listings and IMO nothing that should be in the main focus all the time.