I wondered the same ..I have run mine that way for over 10 years..just changed
points, tune up..etc..the points were grayish and burnt, not pitted..car still
ran fine..I am cautious about leaving ign on, unless engine is running..I run a rebuilt
Skip Haney coil..so far so good..I inquired to a bunch of flatheaders, and most warned of running batt down if ign left on...point life shortened etc.. I like the bright strong blue spark...and have not had an issue in 10,000 or so miles....?? but..I know Henry put it there for a reason......