I dont think you can compare car engine break ins to these engines ..the way we run in glow engines is horrendous to me, I still have a hard time running a brand new engine at WOT the mating of parts is done in a totally different way with glow engines they do not have the oil passages that car engines do... run in a car engine at wot and you then have a very good boat anchor!!!

there are different objectives between various engines
example: when talking about the ring.. in glow engines the object is to seat it against the wall..while in a car engine it is important to develope the taper in the ring against the wall

there is far more to it than just this to which I am not prepared to go into here as it gets off topic..but different engines have different needs you cant lump all engines in one basket