See the screenshot and save file; the mined circles get shape predictions while the pin production does not. (It keeps reusing the same pillars for pushing the top shape out of bounds, exposing naked pins.)
I expect this will be a nofix, but I didn't find a bug report about it. At least this shows that the problem isn't entirely theoretical. (As an idea, maybe instead of trying to predict the shape from circular recipes, the game could have a way to inject predictions for later stages?)