So I have an 10 gallon igloo cooler for my MLT using a domed FB. I want to add either a RIM tube or HERMs to control temps and recirculate. Should I also upgrade the MLT to a SS kettle or Keggle? I don't see many people using cooler MLTs in their HERMs or RIMs builds. Is there a compelling reason to go to a SS vessel? Seems to me that the insulation of the cooler would help to keep grain at the proper temperature and therefore require less heating.