Matt,
star testing in Canberra at this time of year will require a lot of patience from you - I'd suggest that the only time you're likely to get the scope close to thermal equilibrium is if you set up outside at sunset and then set your alarm for 3 or 4 am.
I've been watching the weather reports around the country and we consistently get the lowest overnight minimums for any capital city, last week we had several nights below zero, even though the daytime temps were reasonable in the mid teens.
Based on the data I recorded from last year I'd expect the nighttime temps to be dropping steadily from sunset through to about 2am, so with a closed tube arrangement like the C9.25 you'd have to allow another hour or so after that for the scope to catch up before you could really get to see the optics properly equalised, i.e. see the "true" state of the mirror.
cheers, Bird
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