Benchdogs.co.uk Ultra MFT Workstation accessory T-nuts. The basic variant allows for flat-mounting accessories while the aligning variant can be used with compatible accessories to prevent twisting while only using a single nut. Requires M5 hex nuts and bolts.
Print with T-nut profile oriented vertically, so that bolt hole is parallel to print bed.

Compatible accessories for aligning nut:
The author marked this model as their own original creation.