in pro type 1/24 slot car racing Quads were used in the early 80's. now in some (but not the stock type classes) classes they are up to 6-10 magnet segments on each side. they run on high power tracks.
(slot car forum)
the huge wood tracks they run on, are usually 12v-16v powered with up to 4+ industrial Caterpillar type batteries with a trickle charger on them. they supply haneous and strong amperage thru out the race.
in 1/24 slot we want strong matched magnets. to the point their is no cog / thump as you turn the arm. this results in higher rpm and less vibration.
don't think slotcars are not prevelant to RC.....the endbells you enjoy today were used about ten+ years prior to the RC car industry using them. Prior to 1980, RC motor brushes were on copper levered endbelled Igarashi/Mabuchi type motors. i use to look at my Mura motors and wonder why these endbells weren't used on my RC motors back in 1978.....
also not to mention Armature technology ideas borrowed from 1/24 racing and the GOLD Dust brushes 1/24 guys have run for years now
don't know if the magnet technology will apply to stock RC motors as it does to Mod motors. maybe if istock was changed to a 19T type motor. i think the 27t is limited on being able to utilize this technology......as it is with the 16D class motors used in basic 1/24 racing