Yes, of course.
I think the battery enclosure is certainly a technical issue, as are the certifications the FAA applied to the technology as BOEING interpreted it.
from the photos of the JAL accident, I note some serious charring of the (composite) decking underneath the APU Batt's install site. So that suggests an improvement in separation, battery case from a/c structure might be warranted as well as the isolation of the eight cells within the enclosure. Perhaps an inerting tray, of some non conductive material, perhaps a ceramic.
The space within the E/E bay appears sufficiently large to accomodate a reasonable increase in the space required for an upgraded battery system. Problems of pressure cycling, cell casing, gas production, etc. certainly would impact the discussion?