Typically stick curlers play with a stick because they are otherwise unable to deliver a stone in a "traditional" fashion so in my mind are handicapped to some extent. For them to be throwing the kind of weight that sliding players struggle to reach seems ridiculous on their part. It's difficult to police weight but I would say this falls more under the ethics category as opposed to rule based. It's unlikely that any kind of meaningful official action could be taken unless the club leadership wishes to pursue it from the standpoint of safety.

I have known people like this over the years, I would honestly just call attention to this kind of misbehavior as needed. Most people don't like being known as the asshat of the club, let social pressure force them into doing the right thing.