What are you finding, and why does another service (2020 startup) matter? Can’t support everything.
Some services actively discourage third-party access. Look at the typical MEGA note about this below:
Using MEGAcmd instead of the current way?
On the other hand, despite a somewhat restrictive Filen software license, they seem helpful but busy…
A bit of help with Rust↔Filen API interface? #15
Regardless, feature addition rate to Duplicati is totally dependent on volunteers. There’s no lack of asks, however there’s a definite lack of volunteers in all areas (forum help, documentation, code, testing, etc.).
If anyone is willing to assist with anything (including this, but it looks very difficult), please give some help.