raspiBackup - Supported hardware and software
raspiBackup is supported with RaspbianOS and Raspberry hardware only. Ubuntu on Raspberry will be supported in next release. There is a beta available already. But raspiBackup can also be used successfully on different Raspberry compatible hardware with different Linux distributions. But note raspiBackup requires the /boot and /root partition used in RaspbianOS.
Just test raspiBackup on your environment and be happy if it works. But if it fails or you get error messages there is no support. You may create an issue in github and append the debug log and I will check whether the issue is minor an can be fixed easily. But in any case the environment is unsupported.
Given the fact raspiBackup is maintained and supported for free
1) It's too expensive for me to buy all possible hardware required for tests
2) it's too expensive for me to setup and execute all test combinations
3) it's to expensive for me to execute all tests every time a new release will be published.
There exists a small script in github which tests whether the present environment is supported by raspiBackup. (see here)