If you like radix trees, you may also find this article interesting and useful: https://vincent.bernat.ch/en/blog/2017-ipv4-route-lookup-lin...
I always wanted a comparison to ropes. Every time I see ropes mentioned I always think "why not use RRB trees?". It seems like less housekeeping, but with all the benefits.
What tool were those tree structure Illustrations created with? They look really nice!
I would love to add a good RRB implementation to the persistent benchmarks at [1] to get a state-of-the-art comparison between RRB and BST in a persistent context. Duration, of course, but also number of bytes copied etc.
https://rtheunissen.github.io/bst