2 cents...
You're betting $10000 that this guy will:
- Be around/alive in six months
- Isn't driven into bankruptcy by other unsatisfied customers and lawsuits
- Will remember what he promised
- Will honor what he promised
- Will have time for you
- Will actually do the work this year instead of next
- Etc, etc.
Get it in writing right now.
Get it done this month.
He absolutely must replace the surface, non-negotiable. He should pay for the water, too.
My pool was resurfaced in a week.
Do your own startup (if your warranty allows), and do it right.
Don't let anybody manage the chemistry (if your warranty allows), and do it right. TFP all the way, from day one!
If it were me (and he might go for this if he is that busy), I'd try to negotiate that another plaster contractor do the work. I didn't read your other post, but just the acid wash stuff alone in this one is a big red flag. See if you can find someone better at this to redo your finish. It's a long shot, but ya never know unless you ask.
It is my understanding, and so far my experience, that a deep color like Tahoe blue, plaster or pebble, will mottle over time. I'm already seeing large color variations in mine, only six months old. I was warned by my plaster guy that this would happen (I think I even signed a release to that effect.). I believe it is common. So don't expect a perfect, even-colored surface for years to come. I don't think that is possible with dark pools. I liked my old Tahoe Blue plaster mottling, it looked like clouds to me. And I'm convincing myself that I like what my new pebble is doing in that regard. I don't have much choice, and I wouldn't do it differently. I like the darker color, and that's worth an uneven color palette. Think of it this way, it's more like a lake/ocean in that regard. Yah, that's my story, and I'm stickin' to it!!
Good luck to you! Sounds like you've got a fix on the way, just don't put it off...
--edit--
I don't have experience with quartz, so I'm not sure my thoughts about mottling apply. Others might know. I suspect it does, though...