I have already notified Kyp your question, He will answer soon.
The Mister is property of sorgelig, so new EP core versions will mandatorily go through his approval. The Mister Main feature or drawback is its front-end and included Arm processor.
The developers of the EP core are the Spanish RW group, and they work on other easier FPGAs, like the Neptuno, without a special firmware or front-end.
Of course there are newer versions of the EP core, and they will slowly surface.