Why not?
Does this mean that you believe you are avoiding the ripples? Like you have found a smooth line through the braking zone?
Or does it mean you are riding over them but you are familiar with what ripples feel like and what is happening does not feel like that?
Ripples in the pavement from cars can be pronounced or subtle. Sometimes they are more wavy than bumpy washboard. Sometimes there are other imperfections in the pavement that might not be noticed if one is focusing on avoiding the car bumps.
"From time to time" and "depending on how hard you brake."
So, does this mean that it only ever happens when you brake hard in that one corner and that you are able to control it by braking less (and perhaps sooner?) so that the "time to time's" that it doesn't happen is definitely because you are braking less?
To put it another way, are you certain that how hard you brake isn't moving your braking zone over some imperfection in the pavement?
Is turn five the only place this seems to be happening? Can you re-create these oscillations in other turns or in a praking lot?
What is the frequency of the resonance? Once per second? 2x/sec? 5x/sec?
OK, to my ear, from everything you have said...unless you are certain that are riding a smooth piece of pavement that does not go over the ripples...it sounds exactly like you are describling riding over the ripples and that the bounce is being caused by them. Owing to the fact that it only happens in one turn and your verbal description "car over ruts" ...ruts dug up by cars sounds like a description of ripples dug up by cars. So, are you sure you might not be riding over the ripples ... from time to time?
Now, if you are riding over ruts (or ripples), and "skipping" over the tops, I would say that decreasing the rebound damping to allow faster rebound and allow the wheel to track better or follow the ruts better might help. And perhaps a touch off compression as well. Assuming you can't find a smooth line first.
But...you said that you don't think the ripples are the cause.
So, if you don't think the ripples or pavement are causing the "resonance", I would isolate the situation and attempt to re-create it under some control situation. And as it only seems to be happening in this one corner ...from time to time. Maybe you are connecting it with the hard braking in your mind, and maybe hard braking does coincide with the the "bounce" and is intitiating it, but, maybe the braking itself is not really the root issue. And maybe changing the suspension isn't the answer at all.
Have you asked other riders about their experience in that corner? Did you talk to Dan Kyle about it? You said you trust him, but, it wasn't clear why you mentioned that. Did he tell you to back off the rebound damping?
Anyway, I would get really clear about the conditions, ie walk the track and look closely at the pavement and your RP's and brake markers to know well where you are, where all the bumps are ... and look for a smooth line. Amd ask other riders what they are doing. If you are confident that the suspension was set up to baseline correctly, I would look at that only after being really clear about the one corner that seems to be giving you trouble as the suspension seems to work fine everywhere else?
I mean...why only turn five? And why potentially sacrifice good operation in ten other corners to solve a situation in one?