Having some synchronization between Proton Mail and Proton Pass in regards to contacts/identities would be helpful for keeping track of identities or people you're needing to maintain contact with. Having the two not synchronized means you're tracking duplicate information across various Proton apps. I know others have alluded to being able to synchronize Proton Contacts with phone or desktop contacts, which would make synchronization with Password Pass even more helpful. This would mostly involve using the identities for online forms, but would be a nice QoL feature to have. Maybe provide an button/option to disable the sync per-contact or across all apps.