Keep in mind that kamid is a very young project. It just reached its 0.1 version so while it’s working, there are some caveats.
Future version will relax this restriction but at the moment it’s strictly required for all connections to provide a TLS client certificate.
kamiproxy(1) can help with this, as will relay and encrypt all incoming 9p connections to kamid.
kamid aims to be completely compatible with all existing software that speaks 9p, but at the moment it is not yet. It’s more like 99% compatible, there’s still something missing.
A known bug is that 9front can’t create or write files in a directory tree exported by kamid. The cause is still unknown.