Ground Politics
The chief of NTSB continues to repeat two basic themes, and Boeing responds in public with a type of response intended to resist these themes.
Theme #1 BOEING have experienced two very serious failures in the Battery system as certificated.
Theme #2 Lithium Ion Battery technology is under scrutiny as a whole, the format is in doubt, regardless of chemistry type.
BOEING answers by assertively requesting "test flights" and "repositioning".
They have got to keep at least a few aircraft operating, the chance that the public will see the fleet as collecting cobwebs on the ramp would be damaging.
BOEING answers by suggesting possible "fixes". Improvement to the case, as you propose, and similar, plus a scheme to keep each of the eight batteries isolated from each other, to prevent "propagation" of failure/fire in one cell.
The purpose of these proposed fixes is to plant their own theme, that the technology is "mature", and the failures are mitigable, in spite of the fact that their best efforts "Failed". (See Theme #2)
Technically, I think you have the solution at the ready. Some form of enclosure that will not conduct electricity, will contain explosive forces, flame, and electrolytic material.
These Press conferences are scripted, but that is to be expected. The playing out of the process at the public level is most instructive.
Hersman, to her credit, has outlined the interplay at each meeting. She is a consummate player, diplomatic, assertive, calm, and professional.
BOEING seem to have found their footing. Their initial response will eventually fade, but those who scrutinize the process will remember how they tipped their hand, and loudly (inadvertently) outlined the flawed relationships that exist in the industry.
FAA....speechless. Feckless, powerless, kept.