HERE's a "better than air popper" for popping popcorn in microwave. We used one for five years and couldn't wear it out, but it looked so bad we replaced it.
Just be safe, cook anything and everything in glass in a microwave.
Want the best tasting sweet potato? Make sure it's a Georgia Red variety. We cut them raw in about 1 -1½ inch chunks, place in glass and cook in microwave. Not as good as oven baked, but good enough for the road.