i cant speak for them but i know in my 14 years i have only used breakin fuel once. and it was on the very last motor i broke in. wont do it ever again either. never had any issues in all my years so dont intend to start using it.

one guy used a hudy bench. i did the EXACT method on the the page that comes with the motor, 2 on nitro pro heat cycled for 4 tanks then ran rich for 4 tanks if i remember correctly, last guy who was also on byrons did his own personal breakin.

mine just lost any and all compression and needed a repinch at 3 gallons and by 4 (without getting one) i was chasing the tune all over trying to keep it but it didnt happen.

two had rear bearing failures the others just lost their gusto around the 4 gallon mark. iv never had one go that fast...