By request, a wall mount for the Valve Index "knuckles" controllers. I created four versions of the mount. I believe that all of them will work just fine so I wanted to provide people options. However. there are differences between them which are listed below.

my general recommendation (most recommended to least):
1) screws_above
2) max strength
3) screws_below
4) screws_middle

screws_above:
This is the version that I most strongly recommend printing. Print with the bottom of the mount on your build plate (this makes the controller mount slots as high quality as possible). Supports not needed. It will be difficult to get the middle screw in due to the angle, but it is optional for extra strength.

max_strength:
This version has the strongest strength, with four screws total. The downside to this design is that you need supports. Print orientation is your choice, but I would recommend printing in the same orientation as "screws_above" version to keep controller slots support free.

screws_below:
This version exists as an aesthetic lower profile variant of screws_above. The downside to this design is that you need supports. Print orientation is your choice, but I would recommend printing in the same orientation as "screws_above" version to keep controller slots support free. It will be difficult to get the middle screw in due to the angle, but it is optional for extra strength.

screws_middle:
This is the most minimalist design, as there are no screw plates above or below the mount area. There are only two screw holes. While two M6 screws are strong enough to support the controllers, be warned that it may be very difficult to screw them in due to the tight angle.

note: I'm a big fan of using a drop of hot glue to secure magnetic release cables in the charging ports. It's easily removable in the future and keeps them locked in snugly.

Enjoy!