I now see duplicate listings for the majority of assets in my library, so I assume it does work with Fab. Haven’t actually purchased/claimed anything through Fab on account of it somehow being worse than the old marketplace, but it (Fab) does recognise things I purchased on the old marketplace and says they are in my library, combined with the duplicates I now see that certainly suggest it will work.
In any case, you have found a solution that works, so moot point. Happy coding 