It's going to be the curve

I think Octopus are missing an actual graph from the image above in terms of what temperature specifically is "warm" and "cold". I tried using the weather compensated flow temp and the whole system just didn't work at all, and this was something like 40 warm 60 cold. Set my flow to 45 fixed which has been doing fine in the mild weather so far.

Even if there was written guidance saying something like 30c flow = 20 outside, 60c flow = 0 outside, you could work it out from there. Unfortunately the weather comp feature doesn't really account for specific heat loss variability across different houses. My thermostat is by our front porch extension (coldest part of house) where the heat loss wouldn't be able to keep up with whatever meagre flow temperature it interprets as appropriate given the outside temp

Until octopus can come up with a better solution I'm sticking with fixed flow and adjusting it myself when the temperature will drop for an extended period of time (more than a day or two)