We're on our first TT, but I'm sure this discussion will come up if/when we change units. For what it's worth, we only add states we have stayed overnight in. We use the state magnets on our fridge to show states we've travelled through.
Rob & Kelly, Bella & Brady (Miniature Schnauzers)
2016 Eagle 323LKTS
2016 Ram 2500 6.7L CTD
2015 White Hawk 29REKS Summit Edition (Traded)