tor@afo-tm.org:
IPv6 only exits are still not possible with this patch?
What do you mean exactly with "IPv6 only exits"?
If you want to add a relay to the tor network that has no IPv4 address: This does not work (for a long time I guess).
If you have IPv4 and IPv6 connectivity but you want to allow IPv6 exit traffic exclusively (no IPv4 destinations):
Yes that is possible, just write your ExitPolicy accordingly.