What's wrong with provider doing 1x IPv6 per VPS ?
The only valid reason I read for /64 subnet is SLAAC to be used with radvd setup. with recent Cloud-init a VPS provider can assign any number of IPv6/IPv4 automatically without any DHCP during system init.
Now my reason is very simple I deal with multiple providers, some of those providers can't/won't provide /48 subnet. some of them provide a /112 of a shared /64 subnet and that puts me with different subnetting for every product line/location.
So I decided to go with the IPv4 mindset of assigning 1xIPv6 ignoring all the RFCs (some big DCs are not giving a damn f*** about assigning /64 per server why shall I do that on a VPS) However I'de like to hear industry experts take on on this issue.