Momoe
First, are these the same engineers who designed the Lithium-Ion battery system (and oversaw the whole design/implementation/testing process) in the first place?
No, and yes (more or less).
The design and manufacturing of the various components of the battery systems were outsourced. So the "put it in a fireproof box" fix is Boeing's way of mitigating someone else's design error.
Three, if building an incinerator box for the batteries, albeit a vented one is what these engineers come up with when their attention is focused, I for one am not impressed.
I'm impressed by the fact that the few remaining engineers at Boeing haven't just jumped ship and gone to work for the local power company. With management breathing down their necks and a decade or so of neglect for properly staffed and funded design, testing and analysis capabilities in house, this is about what I'd expect.
I'm just waiting to see if the firebox solution, once signed off by the FAA, doesn't become the long term fix. Following management pulling the budget for solving this problem.
I'm waiting to hear what the final root cause and solution will be. But I'm afraid we may never know. Because no one will continue looking. If they did, the next step would be to retrofit a fix to the fleet. This means millions of dollars more in parts, labor and aircraft down time. The alternative is to fund some poor slob poking around in the lab. With "no solution yet" as an answer.