Smile: Loyalty Program Rewards

I was initially please with how this works - however as soon as you want to use it for marketing it fails. I wanted to invite customers to enter a competition and get reward points (become a member) - however there is no easy way to add this list to SMILE so they are made members and enter the flow...? This is therefore not a useful tool for adding new audiences which is one of the main reasons for loyalty. Making the customer do the work is not ideal. Why can't there be a tag/metafield that once added automatically enrols them.