You know what they say about opinions right?
Well here's mine.
Big cartridge and you probably aren't going to be shooting many hundreds of rounds for hunting. Proof barrels are good barrels and hand lapped so you don't really need a break in per say. They are cut rifled and take forever to settle in on my comp guns. For that reason I have favored button rifled lately in this component shortage. The only part that will break in is the lead where the reamed cut 90Ā° to the lapped barrel. That will only take a few rounds. Shoot a few and clean and repeat should be sufficient IMO. The Proofs I've used have always had nice machine work.
You can do a Saterlee type ladder to go up and find pressure. The test itself hasn't been very impressive in my experience. I can repeat the test three times on three different days and get three different results. There are sometimes trends, but not always. To me the most useful part of it is finding pressure and what the speed is associated with that pressure. YMMV
I think if you use quality brass and sound reloading practices and a powder that isn't real temperature sensitive you will find an acceptable load pretty quickly whether that be Saterlee, OCW or whatever you choose. Are you going to use a muzzle brake?