Basic problem is the FAA lags behind the Industry in Fly By Wire Technology issues beginning with a lack of staff that are fully competent in the technology thus Industry. has to educate the FAA while moving towards certification.
Some at the FAA are reluctant to acknowledge that I am told thus making for some problems in the pace of progress.
I know one Manufacturer included that in their calculations and did not go forward with FBW in one of their new design aircraft.