Well… The diminished 7th chord at the end of the first system is a well-known joker that is often used to escape from one tonality to another parallel universe! The ambiguity of the chord is such that the listener does not know in advance which of its four notes are about to be given a new enharmonic identity! This is, of course, music for 12 equally-spaced notes per octave keyboards, so I see no alternative to using ties to indicate that the player keeps a finger on the note as its name changes. This is really no different from the G that ends W. N. in Elgar’s Enigma Variations, and that is transformed from being the root of a tonic chord to becoming the mediant of the key of Nimrod.
David