Not much (technically speaking) is discussed about recursive self-improvement. But I have a hunch that when we get there, it will be more obvious how important it will be to own your harnesses and models. This is why I am a strong believer in the open-source harness ecosystem.
With companies I collaborate with, I am seeing custom harnesses for evals, RL envs, research, design, coding, marketing, and so much more. I am noticing a lot of Harness Engineering, so I am putting together a set of best practices, tools, skills, and guides.