I have remised this rack mount for a Unifi USG:
https://www.thingiverse.com/thing:4535702

I've taken the sled that is used for a Raspberry Pi, then adapted it to hold a Unifi CloudKey Gen 2 within the same frame. This would allow you to add/remove or switch around your Pi's and CloudKey Gen2 within your 1RU rack.

I also used this vertical mount for the basic shape, but in two and widened to suit the non Plus version of the CloudKey Gen2.
https://www.thingiverse.com/thing:4928020

As always I am including a link to Tinkercad and my hacky work if people want to take and improve upon it at all.
https://www.tinkercad.com/things/0g5Xg2tuo68

At this point the versions are much the same base:

V1.1 - This is solid under the CloudKey + 4mm hole
V1.4 - Open frame under the CloudKey
V1.4 - Hex pattern under the CloudKey + 4mm hole

The hole is there to add a cable tie around the CloudKey to hold it down if required, note that you need a long and thin cable tie or you could join to shorter ones together. Ensure they don't protrude below the sled or it may catch on the frame when you install it.

Creality

Ender 3

No

No

0.2

20