how can you guarantee this 100% based on one single experience? the dome does not get as hot as the CHE, but the dome can still get very hot; mine does to the point where i can't keep my hands on it. most instruction manuals that come with CHEs and domes say to not have the product touch anything that is flammable or could present a fire hazard (like plastics).
if someone can eliminate ANY risk factors with a simple modification, then it should be done. it's always better to be safe than sorry...