I remember it being said CAS is good for the spark plugs, because of the dissimilar metal.
I've been doing that all my life, and on all my assembly bolts, but last year someone said
silver antiseize was better than copper on plugs. Can't remember why. There's also nickel based antiseize.
I have also read that bike manufacturers recommend bike plug threads should not be coated at all, that it affects torque settings enough to make a 7 heat range turn into an 8... (sure, but who uses a torque wrench on plugs?) (I snug mine just enough to flatten the gaskets, not torque them)
And I've also read dissimilar metals (aluminum and steel) and antiseize can combine to create small voltage, like a battery.
Also coated is the wrong word, just a dab is all you should use.
It's all so confusing.