How to incorporate keyboard positions on character level embeddings?
Character keyboard position information is an example of noisy channel model information, an error that depends on how a word is transmitted. It is very common to add noisy channel model information to spell checkers, including spell checkers that use character-level embeddings.

Most character-level embedding models would automatically learn to model common transmission mistakes. Characters that are frequently confused in the dataset would be embedded closer to each other because they frequently co-occur. There would be minimal gain by explicitly adding channel information to a character-level embedding model during training.