I have tried the latest feature which is the sharing feature of Proton Drive.

To share to the user's email destination, there should be a choice of which email address to use because in one proton account can have many email addresses and the email address that appears in the ownership of the folder or file share is the main email, this makes it uncomfortable.

In my opinion, the email of the folder or file owner is quite optional, not to be displayed or can choose which email to give.

Then also for this sharing feature, there is no option of view-only mode or non-downloadable mode. This is important to protect copyright so that it cannot be duplicated.