Mark.........do NOT ever by-pass the "infamous ballast resistor", otherwize yer squarecan ignition coil internal insulative tar will MELT and short out some turns and cause weak sparkies. It takes about 1-hr for the insulative tar to melt, and about 4-hrs for it to re-solidify. Does that sound familiar???
( I have left the swtitc on a few times but can not conclude if this is connected to when the coils have burned up.) ........umm? You do know ONLY the key operated ignition switch powers the ignition coil, don't you??? Leaving the ignition switch ON, will definitely MELT yer squarecan insulative tar and cause weak sparkies.
Many shade tree mechanics actually miss-wire the 3-terminal board under the amp-meter that the ballast resistor is mounted on and un-intentionally OVER VOLT the squarecan coil, melting its insulative tar.
Also check yer 4-nipple wiring; 1,2,4,3 CCW. Many shadetree mechanics gitt sparkies 4&3 swapped. The N-Engine is SOOooo GOOoood it will start and run on just 2-sparkies and won't have enuff hair on its chest to pull the top off'n a soda can. Just as you complain. .......Dell, yer self-appointed sparkie-meister