I don’t have any solid research or results yet, but you might be interested in my notes/discussion on how to approach that question of rewatches: https://www.gwern.net/Media-RL https://www.gwern.net/Statistical-notes#program-for-non-spaced-repetition-review-of-past-written-materials-for-serendipity-rediscovery-archive-revisiter
I don’t have any solid research or results yet, but you might be interested in my notes/discussion on how to approach that question of rewatches: https://www.gwern.net/Media-RL https://www.gwern.net/Statistical-notes#program-for-non-spaced-repetition-review-of-past-written-materials-for-serendipity-rediscovery-archive-revisiter