Can ASEMBL create a stronger part by removing the z-layer notches through milling? Does roughing the surface of a print between layers increase layer to layer bonding by increasing the contact area? Could a smooth, spinning bit melt plastic (through friction created heat) in a controlled way and improve z surface bonding through welding? Could a sub-mm "needle" bit be used to form internal welds (press bit down, then make small spiral to force melted plastic into a "wall" around a hole)? Could a spinning micro ball at the end of a bit be used to weld surface layers together with the idea of getting the z dimension as strong as x-y dimensions? Since new material is not being introduced, the ball would also have to provide enough downward pressure as well as heat to form a weld.
For 1. CNC kitchen has looked at vapor smoothing to remove layerlines and prevent crack propagation, iirc. For 5. Diabase Engineering showed they can use a "hot roller" to burnish TPU prints. They turn out really nice, but I don't know if the strength is improved. The TPU burnishing was from this video: There's also an example of a spinning ball tool at the bottom of this blog post: https://www.diabasemachines.com/post/addition-and-or-subtraction
