Research says that most of the ornaments of this famous aria were obviously added by Johann Gottfried Walther, not when he copied the piece, but later, when he felt that it did no longer meet the taste of the time (which had become French). Unfortunately, the manuscript does not allow to distinguish reliably between Böhm's original score (which is lost) and Walther's additional ornaments (which were squeezed in).
I have tried to reduce this choral prelude to a "clean version" with just a few ornaments as Böhm could have intended it. The Trost organ comes very close to Walther's organ at the Stadtkirche in Weimar. So take it as Walther's first experience with this piece before he decided to "pimp" it.