[9dev]

That kind of emphasises the problem I was referring to; if I pick 200ms, will it stop before doing a proper optimisation because that would make it faster than that? Will it do something stupid to justify pushing from 195ms to >=200ms?

[mh-]

It might! In my prompt, I'm supposing you have some priors here about what's possible. Try saying something like "materially faster". But you need to also make sure it knows how to measure that endpoint's performance on its own, otherwise I wouldn't expect this to work well at all.