Indeed, but in some way the Redis version is a bit too Redis-ish, that is, memory saving concerns are taken to the extreme instead of having a more balanced approach about simplicity. In my YouTube channel C course, I'm showing something similar to SDS in the latest lessons, and I may use SDS again in later course in order to show how to integrate back the useful features that diverged. Maybe an SDS3 maybe a middle ground among the Redis version, some API error that should be corrected (but not in Redis: not worth it), and other improvements.