I like the way you think though, Coinshot. If you could use Alchemal Allocation with Extracts, you could cast level 6 Extracts for the cost of a level 2 slot!
But I guess that's why you can't do it.
As it is, Alchemal Allocation is pretty darn powerful. Basically it means that an Alchemist knows every spell of every class that can be made into a Potion or Elixir, and that's a lot of them!