I know that this was asked so many times, but anyway 64 chapters is much too small amount.
If you create Study for some Theoretical Variation you would need more.
From lichess perspective it doesn't give any benefits to have just 64 chapters. In this case users are just creating multiple studies instead of one and studies became like "Ruy Lopez Study - 1", "Ruy Lopez Study - 2" etc. Instead those could be combined just in one study. Just increase number to 100 maybe or something would be already helpfull.
If you create Study for some Theoretical Variation you would need more.
From lichess perspective it doesn't give any benefits to have just 64 chapters. In this case users are just creating multiple studies instead of one and studies became like "Ruy Lopez Study - 1", "Ruy Lopez Study - 2" etc. Instead those could be combined just in one study. Just increase number to 100 maybe or something would be already helpfull.