Really good point about the ISP just reaching into it's /32 allocation. Also, If there is the slightest chance that you will ever need more than a /56, (I.E. y

Really good point about the ISP just reaching into it's /32 allocation. Also, If there is the slightest chance that you will ever need more than a /56, (I.E. you are anything other than a vanilla home business account) the ISP will almost always give you a /48 right out of the gate anyways, and so you have on the very first day 65,536 subnetworks to work with. After that, everything you say is also true, if the customer starts to run low on those 65,536 subnetworks, the ISP can simply reach into it's /32, and then hand out a second /48 in the rare scenario that someone is using more than 65,536 subnetworks that need to be globally routed.