Endnote 61, from p185, is about "anticonfluential cinema", "...characterized by a stubborn and possibly intentionally irritating refusal of different narrative lines to merge into any kind of meaningful confluence".
It's pretty clear that, having thrown a big bunch of settings, characters, voices, deliberately obscure dates, and a generally non-linear and fractured set of narratives at us, DFW is sort of saying, 'yeah, this will frustrate and probably irritate a whole bunch of people.' But from here we can take it a couple of ways. As a simple acknowledgement of your (the reader's) possible frustration and irritation, even if it's not apologetic it's at least granting that you have an arguably legitimate gripe. That's good, I think. You could read it as a knowing wink at the audience, an attempt to share a cheap po-mo laugh at the text itself, but to me it doesn't come across that way.
Another way to read it is to take this endnote as a warning - this would be the spoilery part since I've read the book once already. Right now, at p 242 if you're on track, you have no idea whether Hal and Marathe and yrstruly and Kate Gompert and 'Madame Psychosis' and all these other addicts and tennis players &ct. will ever 'merge into any kind of meaningful confluence'.
I will tell you that there are connections, and that they are meaningful. But they are not the point of the book. If you (like me, usually) tend to read for plot, and are mainly anxious to find out What Happens, I advise you to temper your expectations. Dwell in the moment of the text if it's a section that speaks to you. Slog through the sections that don't. Look for the connections if you're interested, but don't obsess - you'll have time for that later. Some of the connections and self-reference in the text are subtle and I think brilliant. You're probably a better reader than I am and already found a ton of them. But DFW is not a mystery writer who's trying to keep us hanging on to find out whodunit at the end. He's trying to convey what he understands about people and how they interact and how they function. His insight, and the bizarre, sad, hilarious and beautiful world of IJ he created to share that insight are what are making my Infinite Summer such a great experience.