After refreshing the browser I see that the old o3-mini-high has gone now so I continued my coding task conversation with o4-mini-high. In two separate conversations it butchered things in a way that I never saw o3-mini-high do. In one case it rewrote working code without reason, breaking it, in the other it took a function I asked it to apply a code fix to and it instead refactored it with a different and unrelated function that was part of an earlier bit of chat history.
I notice too that it employs a different style of code where it often puts assignment on a different line, which looks like it's trying to maintain an ~80 character line limit, but does so in places where the entire line of code is only about 40 characters.
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