I haven't read that the tranches are tied to Poet's technical progress except on Agoracom. The only official position of the company I've read is this from Oct. 30th: 

 "With the extended review process likely to continue for some time, and to ensure that all interested investors in DL Shanghai are able to participate, the Company has agreed to receive the total purchase price of US$26 million in three tranches, with the first being a payment of US$8 million on or before November 8, plus two additional installments of US$13 million on or before December 31, 2019 and another for US$5 million on or before May 31, 2020."

It is unclear from this that there are other contingencies or milestones.