Spaced repetition and incremental reading don't have to be a conscious effort or implemented with flashcard systems, in fact it might be better not to, depending on your goals.
After extensive practice with such systems (talking years between physical flaschards, supermemo and anki), I found it leads to shallow understanding and bad linking between knowledge bits, even though I make sure I understand before committing something to spaced repetition. The valuable part looks like to be in the effort of understanding, thinking deeply and widely and summarizing. If you frequently read, practice and revise your knowledge and see how it interlinks, you will approximate spaced repetition at the very least.
All in all flashcard systems taught me how to study effectively by being forced to understand and "atomize" knowledge, so it wasn't useless.
After extensive practice with such systems (talking years between physical flaschards, supermemo and anki), I found it leads to shallow understanding and bad linking between knowledge bits, even though I make sure I understand before committing something to spaced repetition. The valuable part looks like to be in the effort of understanding, thinking deeply and widely and summarizing. If you frequently read, practice and revise your knowledge and see how it interlinks, you will approximate spaced repetition at the very least.
All in all flashcard systems taught me how to study effectively by being forced to understand and "atomize" knowledge, so it wasn't useless.