This should not usually really be a problem. IPv6-only hosting should usually come with a NAT64 gateway, which allows you to seamlessly connect outwards to any

This should not usually really be a problem. IPv6-only hosting should usually come with a NAT64 gateway, which allows you to seamlessly connect outwards to any ipv4-only hosts. If not, you can choose to use the ones provided by he.net or google. I don't see any reason why, with incoming shared v4 http load balancers and outgoing NAT64, most standard http applications shouldn't be able to move to ipv6-only. We've been slowly turning off ipv4 for our load-balanced web apps with little issues so far.