I set 2.8 front and 2.9 rear at 12 degrees Celsius in the afternoon. Given that it is only going to drop to about -4 degrees in the middle of Winter here, shouldn't see any warning alarms for quite a while. Feels happier on the road with a little more pressure, and ride is still not harsh
Moral of the story, put the pressures up as soon as it starts alarming, or preferably before it starts alarming
I've also worked out why the rears alarm first. Given this is a rear wheel drive car, the rear tyres are likely to be running at a higher pressure during normal driving, so alarming at a slightly higher pressure for the rear does make sense