We often use offline methods to get email consent from our members. Because I can't go into the back end and track that express permission, it will soon become extremely difficult to keep that straight.
Thanks for sharing this feedback. If the contact is new to the account you can save them with express consent but with existing contacts you would need to re-upload their address as a different type to change the permission status.
Have you considered sending out a campaign asking your contacts to give express consent on their own?
We have, indeed, already run a campaign, asking contacts to give express consent. But we will also be running offline campaigns, which I suspect will have even better pickup, given our membership. To completely re-enter them to mark them with express consent as you suggest would be far more time consuming than just being able to just change their consent type in an existing contact. Why don't you offer that as an option?