chutney doesn't verify using IPv6 addresses
Even when chutney is using IPv6 exits, it doesn't give clients an IPv6 address to connect to when verifying.
When chutney is using IPv6 bridges, I don't know if it gives their IPv6 address to bridge clients.
This is a significant coverage gap that I think is easily fixed by slight modifications to the chutney templating and verification code.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information