I modified this MRC Throttle holder https://www.thingiverse.com/thing:1994802 from designer SkunkSludge, to fit the WiTcontroller case designed by markwtech. I added solid sides so that supports are not needed. The mounting holes will be slightly egg shaped without supports but I didn't find that to be an issue. I used m3x12 wood screws to mount it. I designed the holder with a cutout for the keypad and clearance for the rotary knob so that the controller still has full functionality when stowed. I also added two indents at the top of the holder that fit the exact curvature of the case when fully seated and help hold the controller nicely. Printed on a Bambu P1S with PETG using the 2.0 strength setting. 20% infill. Print with the holder standing up. I also used a brim but that is optional.