Tried using 5.4 xhigh/codex yesterday with very narrow direction to write bazel rules for something. This is a pretty boiler-plate-y task with specific requirements. All it had to do was produce a normal rule set s.t. one could write declarative statements to use them just like any other language integration. It gave back a dumpsterfire, just shoehorning specific imperative build scripts into starlark. Asked opus 4.6 and got a normal sane ruleset.

5.4 seems terrible at anything that's even somewhat out-of-distribution.