This week I fixed almost all remaining issues with casting and de-molding complex wax patterns. I am getting 100% fill with sprues in strategic places, and patterns don't break on de-mold if I create some thickening geometry (just by cutting parts of the inside mold off) on top of thin edges. This can be removed with a knife just after de-mold, when the wax is still pliable.

I have some remaining issues with sprues affecting quality of important surfaces, so I am re-doing silicone molds to have sprues in better places. Today I also need to experiment with two-part silicone molds.

Fig. 1: almost good enough for final metal cast.

Lastly, here are some videos of the process: