I'm guessing this is what you've read regarding crashing:
http://www.felinecrf.org/symptoms.htm#crashing
I read and re-read and re-re-read that page and I was never sure either, because so many of the symptoms could be just par for the course. I don't know how I knew but Lucky crashed the day before I had him put to sleep. As I'd said before, he could barely walk, he was miserable, he was becoming incontinent. That last one was the big clue for me. I would have had him put to sleep that day, but the vet closed at noon, and by the time he got pretty bad, the weather outside was really bad. The ER vet was a good drive away (compared to my regular vet next door) and he hated being brought out of the house. My vet had re-assured me that while he was miserable, he was not in pain. And he didn't seem to be pained.
I think if your kitty crashes, he won't be eating at all, not even treats. And glad to hear he ate some of the treats. Hiding is definitely something that was always a bad sign from what I'd read - Lucky never quite got to that point. I kept thinking he would, but he never did. So, it doesn't quite sound like your kitty is crashing - yet. But might be on his way to that.
For me, eating has always meant life. That has been the biggest indicator to me of things like "when is it time". It doesn't matter WHAT they are eating, just that they are eating. That's how I see it anyway. Obviously there are exceptions, which is why I say to have a heart-to-heart with your vet. Your little guy sounds like he might be how Lucky was the first weekend after he got diagnosed. He had ups and downs. Probably more of the latter unfortunately, but I treasured the "up" days. That was Halloween weekend. I gave him catnip to see if it had any effect. It did I knew then that he'd make it through the weekend. Weekends really are the worst when it comes to our pets.
http://www.felinecrf.org/symptoms.htm#crashing
I read and re-read and re-re-read that page and I was never sure either, because so many of the symptoms could be just par for the course. I don't know how I knew but Lucky crashed the day before I had him put to sleep. As I'd said before, he could barely walk, he was miserable, he was becoming incontinent. That last one was the big clue for me. I would have had him put to sleep that day, but the vet closed at noon, and by the time he got pretty bad, the weather outside was really bad. The ER vet was a good drive away (compared to my regular vet next door) and he hated being brought out of the house. My vet had re-assured me that while he was miserable, he was not in pain. And he didn't seem to be pained.
I think if your kitty crashes, he won't be eating at all, not even treats. And glad to hear he ate some of the treats. Hiding is definitely something that was always a bad sign from what I'd read - Lucky never quite got to that point. I kept thinking he would, but he never did. So, it doesn't quite sound like your kitty is crashing - yet. But might be on his way to that.
For me, eating has always meant life. That has been the biggest indicator to me of things like "when is it time". It doesn't matter WHAT they are eating, just that they are eating. That's how I see it anyway. Obviously there are exceptions, which is why I say to have a heart-to-heart with your vet. Your little guy sounds like he might be how Lucky was the first weekend after he got diagnosed. He had ups and downs. Probably more of the latter unfortunately, but I treasured the "up" days. That was Halloween weekend. I gave him catnip to see if it had any effect. It did I knew then that he'd make it through the weekend. Weekends really are the worst when it comes to our pets.