This adapter plate mounts onto the factory standoffs using countersunk m3 screws (about 6mm in length). Then the Manta board can be mounted on the adapter plate standoffs using M3x4mm screws.
Since the location of the USB and SD card slots is a bit different, you will need a different front face plate. Here is the one I designed if you're interested. It did take a fair amount of time to draft it, so I hope you don't mind a few bucks to support my work. It is very much appreciated! https://cults3d.com/en/3d-model/tool/ender-3-s1-custom-front-facia-for-manta-e3ez-main-board
The author marked this model as their own original creation.