FWIW, I went to see my options and the volunteer login does not accept my EP login credentials. Attempting to use the same email to register as a volunteer is also not accepted, since my email is in the database. I would need to use an alternate email to volunteer. Probably not an intended outcome.
Last year me and my 9 year old daughter volunteered as field resetters for middle school VRC. It was so much fun. We did it the division my son was competing in so we got to see all his teams matches. I definitely recommend it.