C&H and RC EXL ignitions will fire a .050 gap very well, use the TLAR method...
Not sure about the other ignitions, I HAVE run both of the above ignitions at .050, even took the side electrode clean off a BPMR6F, the engine started and ran but missed at high rpm....
I guess if you wanna use the "accepted" gap use .025 to .035....Anyone thinks a few thousandths difference in the gap makes any measureable difference is WRONG...Unless it's on the fine line of being too close....