OpenUnison VS devspace-plugin-loft

Base OpenUnison - this is the platform everything else is built off of - https://github.com/tremolosecurity/openunison

OpenUnison (but you have to bring along something called Orchestra??)

I'm biased but I do think what you're describing is a good use case for Kubernetes. I work for Loft Labs, we're the company that created vcluster. We do have a commercial product called Loft that lets you manage vclusters and offer them self-service to developers. If you want to get more info on that, the web site is loft.sh.

There are some products available, for example Loft who open sourced vcluster

We run on EKS and use https://loft.sh/ to deploy development environments. The engineer runs the single service locally that they want to modify. Any other services or databases that service connects to run remotely in our Development EKS cluster using Loft and port forwards to the engineers local environment.

Lastly, one day my employer will let my run Loft so that I can provide on-demand ephemeral k8s clusters to my dev + test teams.

Have a look at https://github.com/loft-sh/kiosk and maybe the paid version https://loft.sh/

How many friends? I would recommend evaluating Loft which is free for up to 3 users.

Automate the setup of new k8s environments, ideally they should be ephemeral, disposed regularly and rebuilt by the devs themselves, on demand. This will also keep costs in check, devs don't work 24/7 so why should their cloud infrastructure? A tool worth checking would be Loft

Loft solves this + much more. There are cost-saving features too, so it might actually pay for itself. Don't hesitate to book a demo.

Loft.sh provides self-serve Kubernetes solutions for cost optimization, CI/CD, policy enforcement, user management, collaboration, and more. It helps save on Kubernetes costs by using quotas and space constraints which helps while sharing your clusters among multiple users and teams. Auto delete for idle namespaces and sleep mode for idle workloads also saves costs.