Been a while since I posted on this topic.
Frankly, I started to get a little weary of hearing these chromatic thirds scales and my wife would echo that sentiment magnified with the aid of a good scientific calculator...
I have been installing new window sashes in my house and part of that process requires one to use their right hand as a battering ram (palm strikes to the side mounted balances). That made me hand feel a little sore starting about 2 weeks ago and it is just now subsiding.
However, on a good day when I am warmed up, this thing continues to improve, though be smaller increments than before. If I were in school I would be willing to perform this at the less scrutinized Friday 10:00 recitals that we had nicknamed 'SPASM' - Student Performance And Sometimes Music.
As for the technical things - ascending scales are all playable at the marked tempo of half note = 69, though I prefer to hear the quarter notes at 138. Broken thirds chords (G7, F7 and the diminished) are all pretty clean with the cleanliness being ordered just as they appear in the score. Here is the cool thing. The F7 broken chords used to seem nearly impossible. Now my hand just knows where to go with just the odd occasional lapse if my mind wanders. The key it seems, for me, is to remain relaxed and aware, but not over-thinking it. Trust the force, Luke. Same goes for the pesky G#m descending scales that really presented serious problems for many weeks. Now... very playable, but not as clean as I would like. Even Lisitsis sort of blows through these with some aural ambiguities.
Funny, the VERY first part that I started working on was the last 4 octave descending minor thirds scale. I thought that was likely to be the toughest spot as I approached performance levels. I was right. Maybe it was a mistake to commit to the sliding second finger... but I am locked in now.
Once my hand is fully restored from the pounding in of hardware (there really is no other way to get these things installed) I will record it again you can judge the progress.
BTW, this marks 6 months at this piece. Even at 59 now, I have no doubt that 6 months from now I will have it firmly mastered. Performable on a good day now. By next December, performable on ANY day.