Since you'll likely have to retest formed brass to see where pressure is with the dimension changes, I'd just load them all at 40.5 and dial everything in and shoot. Once formed, do another quick ladder to see where you can safely get, and then load accordingly and make the adjustments needed. FWIW I had to drop 1.5gr to get out of pressure after brass was formed on my 6.5 PRC, I know it doesn't translate perfectly just an example. And my Tikkas will also stamp or swipe brass at safe charges, I watch velocity but bolt lift is king for no mo zone.