Enerox, page-6

I don't see a reason for a redesign with a goal of a larger ZBM

https://redflow.com/wp-content/uploads/2018/10/Understanding-the-Redflow-Battery-October-2018.pdf
This App note which you posted the contents of earlier this year shows that ZBM2s in the LSB is modular.
https://hotcopper.com.au/threads/understanding-the-redflow-battery.4609047/

Though all information available to date suggest that Redflow is focused on selling solutions that do not involve providing a LSB.
Perhaps when production capacity is larger, they will go after LSB sales.