A possible way to solve this issue is to attach a 'keyup' event to the textbox. When the user press any keys, the textbox accepts the entered characters immediately.
$('#tt').textbox({
inputEvents: $.extend({}, $.fn.textbox.defaults.inputEvents, {
keyup: function(e){
var t = $(e.data.target);
t.textbox('setValue', t.textbox('getText'));
}
})
})