Mid to late March

The company is surely in the middle of production probably in Penang (Malaysia) where Flex have a substantial production capacity.
First off the rank will be units already paid for under the discount pre-production offer. Then distribution will start, and sales should begin to pick up speed.
I would expect that Nuheara may be in a position to indicate how things are going towards the end of March.
So no point in worrying. Expect good sales to continue once the system is up and running.
Relax and enjoy.