Hey down under.
I have a 320F my self and I would have tried to adjust the airmix screw. As you do 1-2 soft kicks first when warm and then it starts after 2 or 3 new kicks it seems to me that you give it a little more air under the 1-2 soft first atempts, when you do open up the gas a little. Perhaps it gets a little to much throught the pilot circuit. The pilot airmix screw is placed at the carburators end towards the airfilter. Try to turn this screw 1/4 turn anti-clockwise. This screw should normally be 1 full turn out from bottom position. Try this airmix screw 3/4 turn from bottom, 1 turn from bottom and 1 1/4 turn from bottom if the first advice didn´t help. As it runs normally from cold this I guess is a minior problem to fix. These bikes have character. Threat it nice. Good luck.