How many do you need to make this worthwhile? The ratio of cost of storing a library versus the cost of GETing a library is very low, so the chances of already

How many do you need to make this worthwhile? The ratio of cost of storing a library versus the cost of GETing a library is very low, so the chances of already having a library cached can be very low for the EV to be worthwhile. Weighing that against the chance of downtime is a bit more complicated, admittedly.