It sounds to me as if this is a real warming plate...they don't get very
hot...and are flat. But yes, you would need to do this at a center one or
two students at a time...or have a bunch of them. I can't visualize
drawing on heated anything any other way.
Now you could heat crayons in muffin tins or whatever.....in an electric
skillet...and they wouldn't boil. Using that method requires applying
melted wax...rather than drawing on heat. This as you know, is a whole
different technique and effect.
Even in creative moments there is risk involved..... Like maybe you could
have them draw things...wrap them in wax paper and the place into a hot
electric blanket...for melting! I don't know...that is a close as I can
get. Good luck! lia