I imagine you'd be able to pick up another second or so at least if you took the donut tire off (shown in the last photo) and put on a real tire instead...
Seriously? Nope, not on FWD. For the same reason Dragsters (RWD) have small skinny tires in the front, this one put the donut on the back-- less rotating mass and resistance. I don't know if it would actually make a .1s advantage in this case, but, it certainly would not help (improve times) to put a full size tire back there.
You would be able to drive safely over 45(or whatever the donut limit is?), drive longer than 30miles, and take turns at normal speeds again with a full size tire. You could also drive on the highway without freaking out all the cars around you who are now wondering just how long you've been riding on that tire.
Of course, safety and/or cornering were not the goals of this project... at least not from what I see.