I guess you could add something like "modular aspects" to human form. I'm not really sure if that would be worth any refresh, others are better at judging those things. Maybe -1?
Well, here's what I got:
Personality Change [-1]
Musts: Human Form
Effect: When you change, you change. Select at least one or up to all of your aspects that get changed when you access the powers restricted by human form. When you access those powers, the chosen aspects get replaced by ones fitting the other personality, as long as you are accessing at least one power restricted by human form.