Are you still making 3d parts?
I would like a set of test fit domino's. Currently I have a handful of domino's that I have sanded down on all sides and the top and bottom to allow easy insertion and removal for testing how panels align after making my domino holes. I have the word TEST written in sharpie on both sides so I do not mistakenly use them in the final glue up. A good set would be about 10 in each of the common size domino's. Of course if they were Festool Green there is no way you would use them during glue up.
These should be sized so they are snug but not too tight so they can be removed easily. Sometimes on complicated glue ups using the test domino's has helped me get the glue sequence right. When I first got my domino I had a few situations where during assembly because I assembled in the wrong order I could not get domino's in. Since using my test domino's that is no longer the case.
Let me know if you can make these and what the cost would be.