The official word I have seen on rebound clearing (which I did most of my reading about on the Vetsulin website, back in the day) is that it can take up to 3 days to fully clear. The conventional wisdom I have seen is that it takes a cycle or 2 to mostly clear, but can still take a little longer to fully clear. I don't know where Vetsulin got that, but I can dig up the link if you are interested.
Liver training, now that you say it that way, I think is a misnomer. I don't think it's literally to train the liver not to do it's thang, it's to force the body into good #s for long enough that it realizes good #s are good #s and stops overreacting. As I understand it, if they don't spend enough time in good #s their liver potentially will just keep overreacting and you will basically never see good #s more than occasionally. So that's why you shoot through that to force the good #s until the liver chills out - not from exhaustion, but from recognizing there's nothing it needs to react to.
The idea of feeding the actual low # to prevent a bounce I think is to keep things so the liver doesn't need to react, i.e. keep the #s in a good place to avoid the liver bounce. So although yes that circumvents the liver doing what it is supposed to do, in my view that is something supportive rather than in the "training" or whatever category. Prevent the lows from actually being dangerous, or slow the steep drop with food, and you don't overtax the liver by giving it something real to react too.
What I think you are getting at - the risk of liver exhaustion where the liver just stops reacting - is from what I have read a real danger that is in play if you have repeated acute rebound. If you are causing actual true rebound, i.e. rebound with a real cause like low #s, you risk that one day the liver is just worn out and doesn't do it's life saving thing. Liver training is different though, because there isn't actual danger. If the liver stopped reacting to that from exhaustion (which I don't think is the goal of liver training, it's to get it to recognize there is no danger), they wouldn't actually hypo b/c liver training is about putting them in good #s, not hypo #s.
That's why the repeated sharp drops Sue sees make me nervous. It seems to me it is likely to be causing his liver to react almost every cycle, and sooner or later I am worried it will just go kaput, and since sometimes he does get low nadirs I think that is really dangerous.
I'm not sure if I put that clearly but I think I know what you are getting at Lori and I think there is a distinction if I could articulate it. Liver training is NOT about training the liver not to react to true danger. It's about keeping the body in good #s for long enough stretches of time that the body adjusts to that and the liver learns there is no danger there. So it's like if you have an anxiety disorder and panic when there is no danger. No treatment plan (ideally) would be about training you never to react to anything (ok, discount years of really bad stuff in medical history here, as the ideal probably is not the reality). It's about training you to realize when there's no danger but your body is reacting like there is.
So to me when you are intentionally going through "liver training" it is important NOT to be doing things like causing steep drops or getting dangerous lows (of course those things happen along the way, but as best you can), b/c those are things where you actually DO want the liver to respond (unless you can head off the problem with well-timed feeding and avert the crisis that way). Just seems like it confuses the picture.