In FI, I can play the descending broken chords but not fast enough. All the other problem areas too I’m sure are common to us all. Bar 13 on still doesn’t sound right. When I hear it played well it has a ‘smoothness’ that I’m just not getting. I’m beginning to wonder if the piano’s to blame, lol!.
Practising the last page, I split it up into 3 sections.
119-122 (2 bars repeated)
123-124 (1 bar repeated)
125-126 (1/2 bar repeated)
I loop these and play enough to give them a good work-out. I’ll start to join them together when I’ve got a reasonable tempo.
Re Consolation bar 22. I can’t advise with any authority on how to do this but I’ve noticed it’s rarely played in any of those versions you’ve linked to with any precision; though it’s supposed to be 4 against 3 like FI, it doesn’t come out that way. Instead, the RH is played as a sort of flourish, like bird song.
So I think the trick is to learn to play perfectly the 7 note figure, RH only, so that you can play it without having to think about it. You’ve probably heard it often enough, so you’ll already know how fast it should be. I think then you’ll be able to add it to the LH by figuring out where in the LH arpeggio you want to start it – that will depend on your tempo, e.g., Yi Jong's overal tempo is quite slow but because he plays the RH figure so fleetly he has to start it quite late in the bar, in fact only just before the final Ab in the LH. The result is his final 6 notes are played almost exactly (but relaxed!) as a RH sextuplet against the final LH triplet in the bar - 2 for 1, that's dead easy!
In any case, however you play it, you should be able to focus on the LH arpeggio, forget about poly-rhythms and just set the bird-song free.
edit: I've just listened again to the other 3 versions. Itin, Yong and Barenboim play it NOTHING like written because they've all chosen a slow tempo. The little phrase needs to sound fleeting so they've no choice but to bunch it up at the end of the bar, bearing no resemblance to the score.
Only Horowitz plays it 'something like' it's written and that only because he's chosen a much faster tempo.
Clearly, the message here is "do your own thing"!