I don't run that much advance, probably 28deg. Starting with mikunies I put the chokes on and kick through 1 compression each cyl, unless its very cold weather 2 each, all with ign off, then I turn chokes off, ign on, no throttle and kick. It usually starts. Bumping it down a hill is easier, just put chokes on, ign on and go.
You need less adv because of the long stroke, maybe you could measure how far down the bore the piston is at 30deg, I doubt its the same as with the short stroke, plus the combustion chamber is good esp big bore, so it requires less adv to go best.