Whenever I re-read PF my different frames of mind produces revelatory kaleidoscopic shifts and different emotional responses. Here we find the contrast between Shade's grandiose promises and their trivial outcome - which  is, most certainly, a deliberate tactic.

Deliberate, yes, it it serves what aesthetic purpose? What "abstruse,unfinished poem" are we expected to read?

(Perhaps this is why, unawares, I kept hearing ghosts whenever I let myself flow along its rythm and sounds. This is certainly a haunted dark Canto!)

Check from lines 835-841 [" Now I shall spy on beauty as none has[...]Now I shall cry out as  [...] Now I shall try what none...]

that merge into "And speaking of this wonderful machine:/  I’m puzzled by the difference between/ Two methods of composing:" with a long technical exposition mingled with cotidian remarks. What wonderful machine  does he mean: the iambic motor of versification?

Next, in the  same initial "grandeur" we find, in lines, 902-904: "Now I shall speak of evil and despair/ As none has spoken. Five, six, seven, eight,/ Nine strokes are not enough....", with a ritornello twenty verses later, on line 922: " Now I shall speak of evil as none has..." And yet, the evils Shade ennumerates are merely his personal loathing of jazz, bull-fights, abstract art, progressive schools....The very classic "now I shall spy, speak.. like none has before" are intimately close to Shade's shaving procedures, mysterious metaphors, "two methods of composition", to conclude in lines 936-7: "and now I plough/ Old Zembla’s fields where my gray stubble grows..."  More than a discourse on method, Shade demonstrates it, together with an aesthetic theory ( constriction versus spontaneity?) and a philosophic query on what's life while unaware of his approaching futile death, inspite of Sybil's(?) protection "beneath the word, above/ The syllable, to underscore and stress/ The vital rhythm." 

What are we supposed to hear besides the present stanzas when we imagine that today, as in the days of yore, "One heard a woman’s dress/Rustle"?