I thought Gravity's Rainbow got more confusing as time went on, if you just flow through it yeah its not too bad. But to fully understand the 100s of characters disappearing, reappearing with new names, etc. I definitely found myself consulting notes in the later pages to remember what role someone had played 400 pages earlier. The earlier chapters you can just absorb with no thought for how it contributes to the whole, by the end it is a lot of threads to try and keep in order.
Try Sartre's "Le Sursis". The novel follows several groups of young people as the news that the Germans invaded Prague and war is probably weeks if not days ahead. But it switches focus between groups mid-paragraph and sometimes mid-sentence. Sartre's not known for experimental fiction, but whew.
I felt that by page 180 or so it really starts to hone in on Slothrop’s journey and it stabilizes. You can page back to revisit a character you faintly recall. It was around then I felt I had a grip on it.
