If the second visit happens then, the activation is still only valid for the delta between first/last seen times. So if it's over a couple hours in the coffee s

If the second visit happens then, the activation is still only valid for the delta between first/last seen times. So if it's over a couple hours in the coffee shop, it's deactivated by the time you go home. TACK can definitely benefit from being paired with Convergence, so you don't have to "start cold" the first time you visit a site. Yes, I think their main concern was about admins testing out pinning and accidentally locking their customers to the wrong key due to a configuration error. Perhaps the default UI action if a previously-activated pin has expired and a new pin key is being presented should be to warn the user.