morphgnt
πυκνά in Luke 5.33
Is it the accusative plural neuter of πυκνός (in which case lemma is wrong) or a derived adverb (in which case the part-of-speech is wrong)?
well, it is the acc pl nt., but it's at least common enough that the adverbial usage has it's own LSJ subsection for the adjective, and a separate headword for the adverb. How many times does an adjective need to be used adverbial before it is lexicalised?
As it's currently represented in MorphGNT, there's a mistake (i.e. it's lemmatised as an adverb but POS-tagged as an adjective). I think it can only be decided syntactically in context.
If this is a morphological analysis (especially in the "new tag" branch where we care more about the morphological properties than the syntactic ones) we should probably treat it as an adjective. In other words, specify the case, etc in the "new tag" branch even if functionally it's not an "A" POS.
Then yes, I'd concur in treating it as as adjective morphologically, despite being syntactically adverbial.