I've reviewed this thread and can't seem to locate where to buy your NXL adapter. I'd be interested in one.
There was a thread on DPReview (https://***URL removed***/forums/thread/3973075?page=3) that looked at the electric protocols for the NX with a goal of an EF-NX adapter. There are preliminary electronics but no adapter; maybe potential for a match-up.
In parallel with the above recording time limitation question, are there any issues with over-heating? If so, how is increased temperature handled during recording?