The hotends fit inside a little bit loosely thus making it a little bit rattly while moving but that doesn't bother me. They don't collide with boxes on top so you can freely stack more gridfinity stuff on it.
Printed with PETG on Snapmaker 2.0 with Dual Extrusion Module. 0.24 layer height. Infill is 5% and it already makes it rock solid so you could optimize this model quite a bit.
If you're not scared to see the source I am including a link to Onshape document. Some techniques might be weird since I'm still learning. https://cad.onshape.com/documents/043344ec9e4528629ef1b6b4/w/d2f8ad2adf513d107232769d/e/359e6a9614c10251639aeaca?renderMode=0&uiState=63e543409f97557489c802fa
The author marked this model as their own original creation.