Does the rewrite need to be with Jekyll for the static site generator part? Potentially one could hack things a bit more if its based on a Python-based generator like Pelican or Nikola (with Nikola supporting notebooks natively without the need for plugins). Incidentally, the things that fastpages does better than Nikola and Pelikan, couldn’t they also be implemented as Pelikan or Nikola extensions, to prevent reinventing the wheel?