It's one of those old Colossal Rules that were for a specific fig or two that somehow became ingrained in my mind. When a Colossal steps on an object, I was misinformed that the object is destroyed.

It was recently pointed out to me that, like multi-attack, this is not always the case. So unless anyone can point me to wording that states otherwise, I am thinking that my new ggG006 Dormammu can use the Eleha'al Vine just like anyone else...right?

I really like this headline.

Thanks, that's what we call vine use at my venue.

Destroying an object or terrain was part of the special rules given to old colossals. I don't think there are any Modern Age colossals that have these rules.

Agreed. That ruling is in the rules sheet for older characters like the original Galactus and Sentinels. There is no modern ruling that affects all colossals similarly.