I've had a few conversations with a retired engineer from a Tier 1 OE who manufactured many of the famous Muscle Car wheels.
They did a great deal of testing in the 60s, and found the Pontiac 8-Lug and Buick 12" Finned Drum to be the equal or superior to the disc brakes of the era. The key for both is getting airflow over the fins to get a good temperature delta. They work just as advertised. Problem is that Pontiacs and Buicks had a lot of body wrapped around those wheels! I didn't think to ask if the 'scooped' backing plates such as found on drum equipped big tank/big brake Corvettes would be helpful.
Main drawback of the drums was if the drums got wet such as in a deep puddle, etc. they too much longer to become fully effective again than discs.
The other issue with the 8-lug is that drum is highly sensitive to even minor distortions post machining, which cause the annoying pedal flutter. K-H reached out to find a solution - only reliable answer was to cut the drum with the rim and tire bolted into place, which was impractical for production.
As Paul Harvey would say: "Now you know..... the REST of the story!"
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