To close the loop on this, I wasn't able to get this to work with Piwik but was able to generate a work around with Google analytics.
By modifying Sean's code slightly I was able to get desired view in the "User Report" window. The trick was that eventValue can only be a positive number but the eventAction can be a string.
Code
$(document).on('shiny:inputchanged', function(event) {
if(event.name == 'bins' || event.name == 'col'){
my_value = event.name + "_" + event.value;
console.log(my_value);
ga('send', {
hitType: 'event',
eventCategory: 'inputs',
eventAction: my_value,
});
}
});
Screen shot of User Report