> Still I normally end up using the web interface for ProtonMail as it fits my workflow better and only need to have one tab open in my browser. They even have a nicer looking beta which also has an in-built dark theme at https://beta.protonmail.com

Btw, you can have both static beta web client and offline access to the email messages using https://github.com/vladimiry/ElectronMail even being on free account as opposed to Bridge thing. The app also supports "persistent sessions" feature, unlimited full-text search (body content also gets scnned) and other fancy stuff.