This paper by Jason Lustig on Gotthard Deutsch’s #zettelkasten was fascinating: https://journals.sagepub.com/doi/abs/10.1177/0952695119830900. While there’s an implication that its use didn’t make him as productive (from a writing perspective) as Niklas Luhmann or S.D. Goitein, I might suggest that it made him a more productive thinker and teacher, which in turn bore results in the form of his students who also picked up the practice from him.