Every year millions of people all over the world must learn to live with the fact their loved one will die soon, even if they don't know the exact date, just a doctor's estimate. I would say 0% of those people suddenly embark on a successful shounen-esque adventure to find a cure for cancer, another disease, or some permanent, congenital defect current medicine can't deal with. This series was clearly meant to be a realistic depiction in that way. The dude just had to deal with Isla dying, just like one would in RL. There were so many stupid irregularities in this story, which I have already listed earlier, that you simply have to accept that as a setting, the very core purpose of the plot.

Your Option 1 would have been the traditional Hollywood unrealistic ending, but your Option 2 would have been spitting on Isla's face. It takes a special kind of cruelty to disregard everything your loved one stands for and selfishly do whatever you want with her fate. You have to realise Isla was working for that agency her whole life, doing exactly what was done to her in the end, all the way to the whispered, symphatetic last words. The one thing Isla never wanted to see was a Giftia going berserk after the deadline and attacking their important persons. You think she would have then wanted that fate upon herself? You think she would have wanted to be the special exemption after retrieving so many Giftia from their grieving owners? I think not.