Dear Sir/Madame,

it appears that disabling ipv6 is not possible after creation of a droplet/enabling ipv6 for it.

This is a crucial information that could break the operation of some software that probes and resolves hostnames based on ipv6 if configured.

Please make sure it's listed in the documentation, probably enabling ipv6 should have some warning screen saying that it's the action that can not be undone, like for resize droplet with change of disk size.