Created this to hold the usb storage for my two pi 4's on the rack. This was specifically designed for but should work with most or should be easy to remix for your own use cases.
Feel free to tinker: https://www.tinkercad.com/things/khz2K4PGmmx-1u-modular-tray-for-m2-usb-enclosures
The author remixed this model.
Added tray to hold m.2 sata usb enclosures.