Regarding the pipeline, got it. I'm working on this and am glad you like the CLI-centricity of it.
I am experiencing the same ssh glitchiness that I did with DevPod. Full-screen applications such as Emacs and vim seem to newline randomly. I think this has to do with the fact that whatever Go ssh library is being used changes lf to crlf, if I recall correctly from my attempts to look into things with DevPod. So the ssh functionality is really only useful for running command line tools. The advertised VPN functionality appears to be missing.
The good news is that, unlike DevPod, whatever you're using for an ssh proxy plays nice with Emacs TRAMP mode. Overall, the UX is better than DevPod. I wish I had X11 forwarding or even a non-glitchy terminal, but it seems that the devcontainer ecosystem is set up to only really support Visual Studio Code.
https://www.youtube.com/watch?v=YVlcADaT94o
The sudo-curl-pipe-bash pipeline makes me raise an eyebrow, but otherwise this looks like a step up in ease from faffing about with DevPod. Then again I'm a command line guy all the way, and DevPod is more GUI centric which may play well with other hackers' sensibilities (but it has a hidden CLI of its own).