Another paper of his that I really like combines a few elegant ideas into a simple implementation of bitvector rank/select: https://users.dcc.uchile.cl/~gnavarro/ps/sea12.1.pdf
During this time I got really excited about succinct data structures and wrote a Rust library implementing many bitvector types and a wavelet matrix. [2]
My interest came from a data visualization perspective -- I was curious if space-efficient data structures could fundamentally improve the interactive exploration of large datasets on the client side. Happy to chat about that if anyone's curious.
[1] Paper: https://archive.yuri.is/pdfing/weighted_range_quantile_queri... though it's pretty hard to understand without some background context. I've been meaning to write a blog post explaining the core contribution, which is a simple tweak to one of Navarro's textbook data structures.
[2] The rust version is here: https://github.com/yurivish/made-of-bits/tree/main/rust-play... and an earlier pure-JS implementation is here: https://github.com/yurivish/made-of-bits/tree/main