Since we can't convert cards, I have a suggest that would provide a much faster workflow for transferring data from one card type to another.
I'd like to be able to make a new card of a certain type, and it copies all the data in the currently selected card, placing the data in Notes with field labels. This way, in one shot, I can transfer all the data from the wrong card type, to a card with the proper type. I've been doing this for 30 minutes now, and it is cumbersome.
It could be called Copy to New Card Type, and could use the existing + bottom, perhaps with a modifier key. Or it could be another context menu item below Duplicate.
It would copy all the data to the card's notes field, and set the title identically.