If you have an LXD setup working for your own workloads that's working well for you, that's awesome. Why would we want to talk you out of that? Fundamentally you're getting at the difference between "elastic" cloud services and personal infrastructure. Personal infra is great!

If it helps: Jerome has been working for a couple months on a local, open-source Rust version of Sprites, so you can use the same DX with your own infrastructure. We just think this is the right "shape" for modern sandboxes, wherever you actually run them.