Exactly this, as soon as you can check the tyres and pressures when you get off the bike the better, after a few sessions you'll be bang on. I used to run Dunlop NTEC slicks in my endurance days and they were really pressure sensitive and ran really low pressures on the rear when hot, so I would check the pressure on the warmers ahead of the first session to get them in the ballpark, end of the first session as soon as I entered the pits rear paddock stand on and check again and adjust, second session just check when I come back in, by then it would be on the money.
