I think the foam is to prevent the bonnet from getting hot and protect people from burning hands and bums when they touch or sit on the bonnet
. The foam on my cat has burn marks too.
Mine gets hot but not so hot that it cooks the oil. Oil temps are normal. I still use fully synthetic 5W-30 and this oil holds. Depending on how I drive it remains in gold until 3000kms after change. Most of the time I push it in 1st, 2nd and 3rd. Only complain about the excess heat is the acceleration. Its not as good as when its cold, because of hot air.