The “Curve” of Earth that you during Felix’s jump is an effect called “Fish eye lens effect”. No such curve of Earth, exists.
This is what a balloon launch would look like, only at 1000 mph. Remember, though, balloon launches would be completely different all over the “Planet”. Launching a balloon and watching it slam itself into a building would be much faster of a crash at the equator, then anywhere else on the “Planet”.
This includes flying a balloon (If you somehow managed to get it inflated, much less fly). Travel times for roughly 50 miles, in a balloon at the Equator would be faster than that same distance, closer to the poles in Canada.