There is built-in uncertainty in the postag search. Because the entry in the dictionary is only word-root-tag, all one can rely on is the grapheme (and tag). When the same grapheme has two tags, one must rely on the (difficult to make) disambiguator to distinguish between them where possible. But if there are 2 roots of the same grapheme, how does 'token inflected' work? Does it know the inflections of all the root graphemes, of only one of them?
And for the reverse lookup: it will find (1 or maybe even more) roots for a grapheme, and find the matching tag for all of those, or just one?