Agglutinative grammar seems to be a difficult nut to crack, and I think Malayalam (my native tongue) is likely the most complex language in that sense. I happened to read "A quantitative analysis of the morphological complexity of Malayalam" (https://kavyamanohar.com/post/malayalam-morphological-comple...) which was published just a few days ago which describes some of the challenges, and has an interesting comparative study of various languages including Finnish and other Indian languages that are known for agglutination, inflection, and derivation from a common root.