Since I last posted - they shaved the tunnel walls where necessary so that all trains will fit on the turn. Work has been going 24 hours a day on the stations. There's definite progress at 72nd Street, where i saw workers using the elevators 2 weeks ago. But there's still more work to be done. I haven't been to 86th Street in several wweks, and I haven't been to 96th Street in much longer.
For now, I'm just going to wait and see how soon Phase I will be ready. The way I see it, based in part on observations by others that one won't do well to predict too far ahead with MTA, is:
Phase I will be in use by the public sometime in the next few months.
Phase II should be done sometime between 2026 and 2030.
Phase III and beyond: It's anybody's guess. The cost of Phase III hasn't been budgeted yet, nor have the details of making it been addressed. going based on recent history, work on Phase III will most likely begin when Phase II will be ready for the public, or close. And since Phase III will cover a much longer distance than either of the first 2 phases, and twice as many stations, we'll be luck to see trains running under Second Avenue by 2050.