At the moment Limesurvey Sync creates a new token every time a user fills out a survey. It would be great if you could add a feature that first checks to see if there is a premade token in Lime Survey. I guess the best way would be to compare the email in drupal user database with the token table in lime. The main reason for this request is that without such a feature you can't use token specific attributes and fields. It would be even better if you could also add a feature that only allows a user to enter a survey if there is a premade token. I guess this feature should also check the token uses left field so that a user could only enter a new survey if there are uses left.
A different way to solve this would be if the limesurvey sync could add information to the token during creation. Like First Name, Last Name, Uses Left and token attributes. Even if you do it this way it would still require some way to restrict how many times a user could enter a survey.
Thanks for all your great work!