I am using Pennzoil Aircooled at 40:1 after break in on DA50. Good high RPM (7200 with Menz 22X8) and no overheat. I do no like Amsoil at 100:1 either. Bad to DA50!

Back to the break-in subject. From common sense, the slow 1-2 hour 2500rpm run would provide a better base for in-air break-in. The problem is that its advantage is not quantifiable. And thus people tends to skip it.