I used to use a fogger in mine - Worked well, except the salts in the nutrient solution meant the transducer only lasted a month or so.
I think the heater mat is a good idea, warm roots are happy roots and you don't have the water to do that like in a tank.
I know we love our hobby & doing things that are not really necessary, is just part of the hobby but, I must say that you can get 3-4 times the growth rate from a sealed heat mat set up with absolutely no spraying of misting or anything else apart from light & ferts in the substrate, that is compared to a tank filled with water!
I have several misters I might well try one out just for the fun of it...