correct about egg2maya not supporting collision/collision tagging. In fact, even doing a direct egg import into Maya will convert the collisions to a standard poly with the initial lambert material. (they’ll almost always show up as white or grey in the scene in Maya).
if your egg’s contain a lot of collisions, adn your familiar with most possible naming conventions, you can write a MEL script to read the egg file and do most of the egg-type tagging for you. It probably won’t catch them all in all egg files, but if the right names are used, it’ll at least tag all them it finds with the names supplied.