Hi @dpfog, thank you for your query. I am afraid that the Tobii Core SDK Does not contain a blink detection algorithm builtin so it is up to the developer to create what they believe is an appropriate time counter for that event.
Blinks typically last 300-400 milliseconds, so if you base your own detection function (ie a loop counter when gaze date is receive) in the mid range of this value it may be sufficient for your desire to capture full lid closure.
Certainly, you could trigger an external event upon this detection so as long as you are happy to create your own algorithm, I do not see a major issue. If you would care to expand upon your project intentions such as hardware being used, etc… I would be happy to provide further assistance.