Based on Vertical_PSU_Mount from community Voron mods.

I modified PsuMountSpring.stl so power supply (LRS/RSP 200W) can be mounted vertically on DIN rails in V-core 3 - space was tiny bit too large to fit without modifications. I have my DIN rails mounted using existing holes used for mounting electronics panel.

I own 300x300x300 and cannot guarantee if it will work for other sizes - no idea what's DIN rail spacing there.

Design for a spring steel plate ideally covering 300x300x300 bed with a nice lip to make it easier to grab. Of course you will need a bigger piece to cut it out from.