Weight parameter

[ecsx1]

A very common use-case is to give different weights to mistakes depending on qwerty keyboard distance.
The type 'confurmation' and the typo 'confprmation' have the same distance to both 'confirmation' and 'conformation'.
But it's more likely that 'confurmation' meant 'confirmation' because 'u' is closer to 'i' in the keyboard.
And it's more likely that 'confprmation' meant 'conformation' because 'p' is closer to 'i' in the keyboard.
It's a silly example but you get the idea.
This is just one of many cases a weighting parameter could help with.