Available as an assembled Module and as a DIY project.
This Module is currently available.
Reversible blank panel
https://abyssdevices.com/product/4-hp-thorns-blank-panel/
These merchants probably sell this module. Huh?
Included in 10 Racks, 5 are public:
Specs are approved by the manufacturer
Abyss Devices 4HP Thorns Blank Panel