Let’s say I have a height+alpha map made in COPs, and I like how it looks in the COPs preview material on a plane. But now I want to process like geometry. What would be the most straight forward way to go from COP to a SOP to achieve this. So basically, how to create a masked grid, with displacement, both based on COPs textures?

Promote your UVs to points, then in a Point VOP, drop down a Texture VOP and link to the output of your COPnet using op: syntax. Then simply displace your geometry as desired. Same for the alpha.