One problem with inflectional error mapping is DanGram's disambiguation, which may well discard correct forms for the sake of erroneous ones if the context also contains erroneous forms.
it may not be possible to re-map a finite verb as infinitive, because the same context that would allow the error-CG to do this, may have led DanGram to discard the verb-reading altogether if the word form as such (or any of its correction suggestions) was, say, a noun or adjective.