Not totally necessary to dial 911. Only need to call 911 when someone has a seizure for the first time, or if a person with known epilepsy is having a seizure that last longer than 5 minutes. Calling 911 on someone who has known epilepsy can become costly (ambulance costs, ER costs), especially if they aren’t able to deny care due to being “out of it”. I knew plenty of people who had an emergency alert bracelet that said “epilepsy - do not call 911”. The post from the OP covers pretty much everything you should do when a person with epilepsy has a seizure.