The hot end and extruder parts are readily available as well as third party controllers for the extruder temperature, platen temperature and extruder feed. Those issues are relatively simple to solve. What I am unfamiliar with are the aspects of driving the Shapeoko controller board with the NC code generated by 3D printing apps. I will have to learn more about Laguna’s approach.
Their head just inserts into the collet of the spindle. It looks like a heavily compromised approach, no doubt they will sell a few though.
When I saw the demonstration of their 3d printing accessory, I immediately noticed how limited the Z axis was. Still it looked like they were getting good results. If the price was reasonable, it would enable one to print many simple brackets and repair parts.