I have a pretty elaborate harness setup, I use my own spec DSL to plan and execute code. So what works for me may not totally apply to others.
I haven't used the frontier models in a few months, so I can't speak at all to this latest batch. When I switched over from frontier I found that what I lost in training data, I more than made up for with Pi harness.
Your process seems more thorough than mine. Mine was literally "I like camels". Switching over to OCaml I found wonderful - I had not worked with FP before and I found it delightful, it kind of cured my programming burnout a bit. I hand built a CRUD app in OCaml/Dream but still feel like a rank beginner, especially when it comes to actually writing code, lol. But I'm getting much better at reading it.
I think the typing and structure of OCaml is a great fit for LLMs, but also the proximity to other things like DSLs, formal proofs, and algebraic structures has tons of untapped potential.
I'm having an absolute blast with it. I like programming again.