It could be useful to be able to connect into a Proton account from an untrusted device, without compromising our main password. For exemple when we visit a country that has a high chance to hack our device.

This could be a new password used for that purpose. To be secured, when we connect with that password, we shouldn't be able to edit the account settings. There could be restrictions on action that can be performed like we can't delete files in proton drive or we can't see the password of some service in Proton Pass. The best would be to allow the person to configure what is accessible with this way to connect.

There should also be an option to automatically disable this password. Like after 2 weeks (it should be configurable).