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GitHub User: tomant
I was thinking along the same lines. The logic is very simple. Set the guest field to false when updating the attributes within the update action. If it is the user's intent to become a full-fledged member, they will input the information required to submit the form to the update action. Bottom line, there are very few reasons to set the guest field to true again, thus setting the guest field to false on each update will easily circumvent the issue of converting users.