A.
Unfortunately, at this moment, there is no clear guidance.

When the safety of other passengers, the crew and the aircraft is considered, any item which are cannot be certified as being not dangerous, or any item that has not been treated as mandated in the regulations, must be treated as still being dangerous.

ICAO is in the process of suggesting implementation of Mar ing the lithium battery casing with a simple comprehensive Mar ing certifying that the battery had passed the mandatory UN test. We would have to wait for this outcome.