Change it? Yes. Hurt it? Probably not. You could reserve half of the last addition and put it in the pot about 5 minutes before you start cooling it.
I must say, I've never seen Fuggles & Chinook used together for bittering.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk