Hello!
With immutable Linux distributions gaining popularity, perhaps there's a chance you could build an AppImage versions of your applications. That way you could provide support for all distributions alike.

There are also community-made wrappers for your applications on FlatHub. I believe these are not supported by you, I would appreciate you taking a stance on them. They look legitimate, as signed by "Proton AG", but could in theory compromise security of users.
Example:
https://flathub.org/en/apps/me.proton.Mail
I'd say either you provide the Flatpaks, or outright reach out to Flathub to get them removed.

Kind regards
Paweł Olejnik