Hi Val,
Currently we don't have plan to support ZSL with the flash enabled.
The reason is the flash sync logic in CameraHAL is pretty tricky, probably not possible to implement customized logic for ZSL.
One alternative is to set the flash mode to torch the whole time but this is not recommended (flash is not running at full power so the amount of lighting is limited).
So we are disabling ZSL when flash mode on now.
Best,
Kailiang