It looks like rsync.net is indeed compatible with Windows, just perhaps not out of the box. Keeping in mind that SSH on windows is somewhat new and I haven't really tried it with a service like this yet.
If you can get command line access to rsync.net with openssh and either CMD or Pwsh, then robocopy can forklift your stuff. This is without even getting into the weeds of the fact that WSL exists...
I am also seeing that some documentation exists for pointing Veeam at it, which is my preference. I don't run any metal computers that aren't hypervisors and using that to back up my VMs, be they windows or linux, is my preference.
If you can get command line access to rsync.net with openssh and either CMD or Pwsh, then robocopy can forklift your stuff. This is without even getting into the weeds of the fact that WSL exists...
I am also seeing that some documentation exists for pointing Veeam at it, which is my preference. I don't run any metal computers that aren't hypervisors and using that to back up my VMs, be they windows or linux, is my preference.