The baby face blaster is in no way overpowered. Before the sandman was nerfed it was pretty easy for scouts to escape Hale and no one was crying for nerfs at the time.
Being at 20 health requires scouts to be very careful with their double jumps, as a quick fall can easily kill them. Hale can also use rage on the scouts, that's one of the easiest ways for him to kill any class. The whole reason people play scout on vsh is for his good mobility to escape Hale, which is also what the bfb rewards. Also, in order to get a boost the scout has to be up close to Hale, and being careless can get you killed pretty fast. The boost doesn't last long either. Ammo is also another thing that gets chewed up pretty quickly. There's only so much ammo you can get until you're the last one alive as scout, almost leaving you defenseless against Hale.
If you think this is true, then you have not seen Pyro. He can airblast Hale and can flare jump anywhere you wanted at a low cost with no risks. When I was Hale one time, a game was dragged on way to long because there was a Pyro who just camped on a mountain with a demo and kept airblasting me off. Each time I raged he either airblasted me before the stun hit him or when he went off the mountain the demo came in and launched me away with his grenade launcher, allowing the pyro to flare jump back up. So no, Pyro is the one that actually wastes time.