I used PETG.  50% gyroid infill, 4 top and bottom layers and 4 walls.  Lay on its side and I used PLA as support on Bambu X1C.  It needs support of 5/16 Inch slot such as tree supports.  It uses a t-bolt and knob as a Hold down for t-track.  It offers good support and holding pressure while not as hard on bits.  It can be used for hold downs on CNC and for jigs for the wood shop.  It is patterned after aluminum hold downs.  The end is slopped so you can see exactly where it contacts the item supported.  It can be used with a ¼ inch bolt or 5/16 T-bolt and a respective knob.  I did not supply a knob as there are many available on 3d  model sites.