Please consider hosting a separate caldav and webdav service.
I know, I know, you don't support that. But PLEASE consider supporting it at least partially. I want Proton to be my one stop shop for security and identity.
Consider this. In order to be able to move to a privacy oriented Android release, I have to manually install APKs, switch to another authenticator because Proton Authenticator is not available as trusted build, and I have to pay for another service to store my contacts. (Also see my post on Obtanium)
The message is: as a non big tech customer I cannot really use Proton in a safe and integrated way. I am paying full fees and still have to piece together my security manually. It is just not sustainable.