The link in the OP is broken, but the form is still there -
linkI signed up and have reviewed the first couple of drafts. There's still a lot of material to be worked on so I would have thought new beta testers would be appreciated.
Strands of Fate was definitely one of the most mechanically defined versions of Fate 3 and gave you more to work with than other Fate instances. Fate Core went lighter again, so SoF is now quite a divergent arm of the game family. It (SoF) has been described as the result of Fate and GURPS having a baby. The extra crunch is mostly in character definition, with there being explicit powers and abilities defined. The game play is (at it's core) a little more crunchy that regular Fate as there are different 'degrees' of consequences, including ones which always have an effect (for example - darkness). But there aren't endless lists of specific modifiers for different types of action or activity.
It could have been big, but fell between two stools so neither people into more 'simulationist' nor people in to 'narrative' games have adopted it as their preferred choice. And the release of Fate Core shortly after pulled the main Fate community even further away from crunch. The new edition of SoF seems to be more it's own thing.