I have heard that some clone-a went into jens scan doubler. Do not know if it was true.
The ECS Indivision flickerfixer/scandoubler contains the ECS core from the CloneA. That's it though, none of the AGA Indivision versions contain a CloneA AGA core.
I heard someone say Natami was closed. I do not think they are keeping it closed source.
Unless they changed their mind.
Read:
http://www.natami.net/knowledge.php?b=2¬e=38307&x=0
Clone-A would be nice for elder boards.
I believe you are mistaken about what the Clone-A will be, it is far more likely to be a standalone product rather than a drop-in replacement for Amiga chipsets, especially if it's aimed at people who don't have an Amiga already. It might have been demonstrated linked up to a real Amiga 500, but that was just to show off how close to the real hardware it is.