Had an update on my Support Ticket after I questioned why they'd sent the exact same TGSP again...
"This is Drew from the support team and I am handling this ticket.
I want to explain this: To ensure the curved screen protector offers optimal protection while maintaining the sleek look of the OnePlus 3, the colored border extends over the edges of the display by approximately 0.9 mm.
This mean that it is design not to cover the edges. You can have it review on our official website https://oneplus.net/oneplus-3-curved-tempered-glass-screen-protector."