The official Flatpak for Feather is not hosted on Flathub due to security concerns.
- Flatpak app · Issue #47 · feather-wallet/feather · GitHub
- Installing Feather on Linux | Feather Wallet Documentation
This means by default it will not be possible to install unverified or non-freedom software Flatpaks.
If this means that installing Flatpaks from remotes other than Flathub is not possible by default, I would ask you to reconsider.
I’m referring to users choosing to install Feather using Flatpak here, not whether Feather is installed on Whonix by default. Although, I would of course like to see the latter happen some day, if there is a way to achieve this without compromising our release security. (All releases must be bootstrappable, verifiably reproducible, and users must be able to easily verify the signature).