[Jake Blake]

" Any thoughts?"

The thought of wrapping resistance with potentially flammable material doesn't set well with me.
In normal operation, capacitors generally do not get warm, . . .  but we know that current passing through a resistance does create a certain amount heat, as a natural occurrence.  So the next question becomes , "How much more heat could the polystyrene take before creating an unacceptable hazard over, say, a naked power resistor?  
Just a thought.