"Where is the fork button?"
Currently the Fork button is hidden because forking is not supported by Heptapod and Heptapod workflow is not based on forks.
Many people used to Github / Gitlab / Bitbucket look for a Fork button. I had some questions on that by people looking at our new repositories on foss.h.n.
Some people who don't find the Fork button won't ask.
A solution could be to have the standard Fork button, but that it triggers the apparition of a text explaining the situation and giving links about the Heptapod workflow. It could be better than no Fork button.