It is very likely in my opinion that the $5 million final payment was held back as a bargaining chip. What impact did Sanan have on this agreement? Was POET's plan to use DL as a supply bridge until Sanan was ready for OI enabled laser and detector chip production or was Sanan part of the bigger picture with all 3 companies?

There is a lot  that we do not  know but I think we should consider that unless DL is part of  a Sanan consortium then DL's OI products will have been severely limited to  just the sensing markets.  

I do think it is fair to conclude that the Sanan agreement timing played a role. And it also of course points to the viability of the OI platform for large scale commercial development for advanced optical integration.

There is still so much we do not know. Who else is involved in that part of the world? Who is involved in North America? What about the modulators. Will POET continue to use existing suppliers ie AMF for Si modulators or are their others in the supply mix now?

What about the contract manufactures that they have established. Will they be maintained to  ensure a diversified supply chain?