Hi Purefusion,
For the use case you mentioned and use case for "miss selecting", which will have very, very low display times -- we set use 300msec based upon GOMS numbers to filter them into different category.
Also, the timing is set as 5 seconds to defining either people "stay" or "switch". We will be happy to discuss with you on these numbers if you are interested.
Could you please describe more on your behavior of "tab-closing parties"? are those tabs you close all near to each other, or they could be all over across the menu bar?
Thanks for raising up this discussion. We'd love to have more people like you helping us in details! :)
Jinghua