I’m ready to become a
floweret
Or a fat fly, but never, to forget.
And
I’ll turn down eternity unless
The melancholy and the tenderness
Of mortal life...your gesture of dismay...
I'd been arguing, quite recently, that both Shade and Kinbote ( together with the Readers) are Nabokov-pawns, being juggled by his "plexed artistry" ( the Reader, just as VN has stated somewhere, is part of his fiction: the reader as engulfed by his work and his thoughts included in its "fiction"). Still, independent judgements are still possible and mine is that Shade can never be Kinbote.
John Shade lovingly addresses Sybil in a way that Kinbote is totally unable to envision, feel, value.
Even a mad split-off part of Shade ( emerging as Kinbote) would be able to write anything even close to these lines, although Shade, as Kinbote, would be capable to write the commentary and the Index.
Besides, Shade admits that "he is ready to become a floweret or a fat fly" (a homosexual Kinbote or a Botkin parasyte), but never to forget... since he'd even turn eternity down to guard intact his private memories: for him, life-ever-after, without Sybil, is just impossible to accept. Isn't this just a typical VN-tease?
If we transform Shade-Kinbote-Gradus into a single literary figure, Shade would, necessarily, forget Sybil's gesture of dismay, her wonder at an airplane leaving a trail against the sky, etc etc.
His parents were preterists, so is he: every detail, emotion, emoticon counts for him. Whereas Kinbote...well!
To have Shade become a "floweret of a fat fly" would endanger VN's project... at least, that's how I think about it today.