Rhythm is one side of the coin and sense is the other...... The illustrative examples bring out clearly the nuances in the variations of the discussed line. Let's consider the line (similar to "His desire he has made a hedge") "His prayer he has made a ritual". This can be read : his prayer has become a ritual. Consider the line with "into" introduced in it and prayer changed to prayers "His prayers he has made into a ritual". I believe this can pass off as : Unbeknownst to him his prayers have become a ritual. I think when the becoming is something negative then the connotation need not necessarily be a "deliberate, knowing, effort-full transformation". Now lets involve a plurality of things instead of a prayer "His offerings, prayers and chants he has made a ritual". I am wondering whether its not preferable to have in this case "His offerings, prayers and chants he has made into a ritual". Then there is something else. The lines that follow "His being's kinship to infinity He has shut away from him into inmost self" bear some resemblance to the preceding ones. The scan of the last line is identical to the one where the "into" has been introduced. In the earlier line his hopes, interests, desires...he has made "into" a hedge, while in the last line his kinship to infinity he has shut "into" inmost self. I would be curious to know if the "into" in the last line found its way up to its predecessor. Interestingly enough, I will say that after re-reading the 3 lines (the line in question and 2 preceding ones) "he has made a thick and narrowing hedge" can certainly hold its own. There can be a very short pause after "has" after which the trochees will naturally follow one after another to close with an iamb.