I know you gave suggestions to use Drag Script to capture Bias and Dark but I prefer using graphics like Sequence from OnTheFly window. We know that there are two sequence sessions, one is called “Sequence” and other called “Auto Flat”. Why not add a third one called “Auto Bias and Dark”? It would be a very simplified version of Auto Flat except that it would only connect to the camera and nothing else, there’s no reason for other equipment to be connected like mount, etc.
Simply clone from Auto Flat and strip out unnecessary stuff like filters (bias and dark don’t need filters), no mount controls, no Min/Max Exp, no target ADU, etc.