We did. Our use case is spinning up containers on demand to user actions, giving them ephemeral, internet-routable hostnames, and shutting them down when all inbound connections have dropped. Because users are waiting to interact with these containers, we found the start times with Kubernetes too slow and its architecture to be a bad fit.
We ended up writing our own control plane that uses NATS as a message bus. We are in the process of open sourcing it here: https://github.com/drifting-in-space/spawner