I don't really understand what the urgency with the smaller /...

I don't really understand what the urgency with the smaller / sample batch of wafers was?

17th May:
As soon as the wafers have been received, inspected and validated we will announce the results to the market

6th May:
Prior to delivering the wafer, the vendor informed the company of the potential for low pixel yield, which was the result of steps they took to expedite completion of the wafer. The vendor assured the company that all necessary adjustments to improve pixel yield have been implemented for the balance of wafers.

So they improved the process, but rather than waiting for the whole batch to undergo the newly improved process, a subset of them were manufactured on an "expedited" basis.  Any reason they would do that - apart from perhaps an urgent need to demonstrate the validity of the technology?

Either way, if the announcements are to be taken at face value, we appear to be on the cusp of success - which might explain some of the delay here.  If the pixel yield is acceptable there is far more to do from a PR/Contractual/Disclosure perspective than we can probably imagine.