If you don’t mind sending me the src for the C# code your’e using I can compile and test once I’m home tonight. Or were you mean you did a local build and tested that?
I meant test out Duplicati with the customization. I would recommend a spare machine or VM so that you don’t affect Duplicati running on your production machine. On the spare machine/VM, you could install Visual Studio 2019. Not sure how familiar you are with GitHub - since my PR hasn’t been merged you’ll need to fork the Duplicati project and then merge the PR into your fork.
If you want to go down this path let me know if you need any pointers.