Do you think it would be possible to port rclone to fully work in webassembly and https://dotnet.microsoft.com/apps/aspnet/web-apps/blazor ?
Possibly... Though the http transfers would need re-working to go through the browser interface.
I did spend a bit of time thinking about it but I didn't figure out how to do the http transfers.
Go has a wasm target which I used to build a simple game here: https://www.craig-wood.com/nick/johnroids/ so that bit works quite well!