There's a trade off, yes you get better charge cooling having the injectors further out, but, the further the injectors are from the inlet valve the harder it is to tune for transient conditions as the lag time increases and the amount of acceleration compensation because the area of wetted wall/ size of the fuel pool gets bigger.

It all comes down to the fact that petrol/ gasoline is a mix of hydrocarbons and the heavier ones don't actually evaporate unless the manifold is heated (goodbye charge cooling). This doesn't matter for racing but is a pain for cruising around, it's almost impossible to get rid of all the flat spots. It also means you have to run richer mixes all the time to make it driveable. The other issue is it varies more with ambient conditions.

I say this from experience since my current setup has the injectors mounted ~500mm out from the cylinder head. I now appreciate how you end up with a better overall package if it's easier to tune.

The best place for the injector is in the cylinder, then you get the best of both worlds.