Terminal / command line support
For when building the desktop apps (especially linux), it would be tremendously useful if it can integrate with different terminals to achieve the following:
fill in credentials in terminals
encrypt / decrypt ssh keys automatically before being used
alert on unencrypted private keys found locally (or even store the keys in proton pass if the user wants this and use the keys for authentication directly from the app to the terminal session)
Secrets Vault (something like the one made by Hashicorp, but within proton pass) which can be used in scripts or commands instead of using the actual API key for example.
Further ideas for you. Locally hosted encrypted storage synced to drive, shredding files (zero sector 3 times)