Thank you for sharing! I’m glad you added the safety indicator
Just to confirm, when you tried curing before the additional heat shield, were you flipping the substrate upside down? That is a step that is sometimes missed. The reason we turn the substrate upside down is to get the ink as close as possible to the heated bed and ensure it gets up to temperature.
Are you able to post some pictures of the type of finish you are getting now that you have been using the heat shield?