I had similar requirements. I switched to Baikal, which has been happily running in a docker container ever since.

Im using borgmatic, a wrapper around Borg that has some extra functionality.

Very happy with it, does exactly as advertised.

Wireguard-easy is plain old wireguard with with a nice web interface for management, that’s all.

It’s easy to set up and use, I’d recommend it.

You can sync easily to another device on the same network via ssh for example. You can also call a script automatically after the backup has been created and do your custom stuff in there.

I’m really liking borgmatic myself as a wrapper for Borg.

EDIT: I don’t have experience doing full OS backups. I only make backups of specific directories.