SuperMemo 19 (2024 - Desktop/Windows) has incremental reading support

https://super-memory.com/help/read.htm

Disclaimer: AnkiDroid maintainer

I don't how well it works in practice for long texts, but for song lyrics I've used this Anki plugin: https://ankiweb.net/shared/info/2084557901

It takes a text, and creates a bunch of cloze deletion cards, each presenting you with a number of lines, and asking you to recall the next line.

I guess it matters how long it is and if you need to know it exactly, and how long you need to retain it. I had to memorize 50 to 100 word phrases and I chained them together with index cards. The first sentence is the cue for the second, the second for the third, etc. Carried them around in my pocket in order and started from first a few times a day until I could do the whole thing. But I only needed to know it exactly for a few weeks usually.

I've gotten tremendous mileage out of exporting book highlights to BufferApp.com and setting them to release only once per day or so. Shuffled, they pop up days, weeks, months after I've put down the book, re-igniting its themes as they spark discussion.