I couldn't find any Gridfinity bins like this so I made one to suit my needs. I made it so that the outline fits the calculator when it's protective cover is slid on the back. I prefer keeping my calculator like this so it is always ready to use (without taking off the protector).
Made with FreeCAD and the Gridfinity workbench. The files are attached for your consideration. No particular print requirements, just print it in whatever material and layer height etc suits you.
Gridfinity dimensions: 5u x 3u x 3u (y,x,z)
The author marked this model as their own original creation.