What happens to the tokens (resources or damage) when the card change of type (unit -> Development and Support -> Development)?

For example with the following cards:

So far, I've been thinking that if the card can't support the token type, for instance a building having damage tokens. So after stone to skin effect ends, the damage tokens don't serve a purpose. I would say take them off if they can't be directly tied to the card type. I don't think there is an exact rule anywhere to explain this situation, yet.