When "Sticky Contact" is turned on in the order form, it seems that whatever customer information is set there can no longer be changed in future orders.

I realized this when doing order tests on my own site. When I change the name, email address, etc.. from the pre-saved sticky contact and submitted an order, it turned out that the info defaulted back to the pre-saved customer info. If the sticky contact info is set in stone forever like this, customers can not make orders with new information.