FYI you should be aware of the Titan protocol. This lets you write to a Gemini server. Authentication is done via client certificates. So, there would need to be some scheme for associating client certificates with existing user accounts.
=> transjovian.org/titan Titan Protocol
=>
https://lists.orbitalfox.eu/archives/gemini/2020/000528.html Client certificates
=>
https://lists.orbitalfox.eu/archives/gemini/2020/000987.html Client certificate musings
I was not familiar with client certificates. But the Lagrange help file has a primer in section 1.6.
=>
https://git.skyjake.fi/gemini/lagrange/raw/branch/release/res/about/help.gmi ## 1.6 Identities (client certificates)
=>
https://www.ssl.com/article/private-and-public-keys/ Private And Public Keys
Section 4.3 of the Gemini specification also talks about client certificates.
=> gemini.circumlunar.space/docs/specification.gmi 4.3 Client certificates
Lagrange added support for Titan in version 1.6.
=>
https://github.com/skyjake/lagrange/releases/tag/v1.6.0 Lagrange v1.6 Release Notes
Maybe Titan can be added to the todo list for Flounder. Then we would be able to interact with Flounder without requiring HTTPS or SFTP.
Regards,
-- Mike