I've recently upgraded my Ender 5 Plus to a Mercury One.1 and while I don't have a proper electronics enclosure yet, I wanted to have all my electronics mounted in the original case for now.

In order to have my Raspberry Pi and the Octopus Pro in the enclosure, I had to relocate the relay to make room for the Octopus Pro. This model attaches to the original PSU with 4 M4 screws and has mounting holes for the relay and a Pi. It has space for 4 M3 heatset inserts for the relay and 4 M2.5 inserts for the Pi. The model is missing some spacers to lift the Pi up, so don't overtighten the screws. 

BOM:

• 4 M2.5 Heatset inserts
• 4 M3 Heatset inserts 
• 4 M2.5-8 screws for attaching the Raspberry Pi
• 4 M3-6 screws for mounting the Octopus Pro 

The mount for the Octopus Pro can be found here.

I've originally printed the mount with a too large gap between the two psu attachment points. I've since updated the model, but I haven't reprinted it, since this is only a temporary solution for me.