The big distinction made in Lila is between dynamic quality and static quality. Dynamic quality is Quality in ZAMM, i.e. the immediate, moment-to-moment recognition of something's awesomeness level, but also in ZAMM, he wants us to recognize quality in classical (as opposed to romantic) forms, for example, the quality of the structure of a motorcycle. Since dynamic quality is instantaneous, and we can only have (roughly) one thing in mind at a time, it would seem to rule out any kind of body of quality knowledge, but that's clearly not the way judgments work.
Pirsig stresses that we make Quality judgments first, and then figure out later how to characterize them. But certainly this doesn't have to the be case: often we have a standard already in mind, and we explicitly apply that standard to something and judge it positively or negatively. Judges are supposed to do this, for example. Now, you could say that what judges do (looking at legal precedent and seeing how a new case stacks up) is cold and impersonal: they don't necessarily feel the verdicts they issue, and in fact might have feelings contrary to what they judge, but still, that doesn't mean they should overturn all legal precedent on a whim.
Pirsig gives the example of music: I can hear a song and have dynamic approval of it, but then after I listen to it a lot, it no longer thrills me. I can still recognize that it's a great song, even if I'm not in the mood for it. I will recommend it to others and probably hold onto the recording so I can enjoy it more later when time has passed and made it fresh again or when my mood shifts.
This step is absolutely necessary for Pirsig to support any sort of ethical system. If you're read ZAMM and think that value is all subjective, that then you might judge murder as high-quality and who am I to say otherwise, then you don't understand Pirsig. He's actually very much a fuddy duddy about ethics: while he criticizes old-style Victorian morality as hopelessly outdated, the solution is not to just reject it and do what you feel, but to engage with it: see what worked and what didn't, what makes sense and what doesn't. He wholeheartedly approves of the effort to be moral, and in fact things this moral acculturation has been historically essential for overcoming chaos (think Hobbes's state of nature).
So part of the freight in that "train of experience" that Dave described on the episode is a set of standards we've already developed, or more likely inherited. There's nothing wrong with those being there, so long as we remember that its original source is dynamic quality distinctions by actual people and nothing more.
Perhaps I shouldn't say "part of" the freight, here, though. Pirsig insists that anything picked out as an element in perception, or encoded in a system of thought, is done so for Quality reasons, which is equivalent to saying that there was a sufficient reason for it being done so. Any persistent idea, from a private obsession that goes round and round in your head to the dictates of a major world religion that get promulgated through the centuries, is there because it met some need, fulfilled some function with success as compared to the alternatives present at the time, it passed some Quality test.
In Pt. 3 I'll say more about how Pirsig thinks the various Quality tests are hierarchized, which determines how moral conflicts should be adjudicated.