I have a really niche use case that this fulfills. I have perfect pitch, but terrible working memory (can't remember more than 4 notes at time). This is a nice way to try to improve it.

Very nice! One of my friends is the exact opposite: they have a pretty poor sense of pitch but a prodigious working memory. They can take a brief glance at a couple of pages of sheet music and instantly reproduce it.

Hope this helps you on your musical journey~