OzMo:
I recomend a good long break in period following the recomended procedure. 1/2 a gallon is a good start. Don't get in a big rush on setting the low end. I think they will last a LONG time if broken in right. Like all ABCs NEVER run em lean and just a LITTLE rich all the time.
Good advice for a "sport" engine. In addition you can be assured of always coming in 4th place in every 4 plane heat in a pylon race.
Of course your method may have degrees of lean and rich. A long break-in with an ABC in the rich mode is needed when you only want to wear off the top of the piston so the engine does not do what a true ABC is designed to do, which takes a fair amount of heat at high RPM. That is the tapered chromed brass liner expands to accomodate the aluminum piston's expansion.
OTOH so many advertised ABC engines are really not, but ABN at best.