I had not. I wish I did when I was writing this book as it is a great word.

I have heard of "moderation" (stoicism), "goldilocks" (fairy tales), balancing yin-yang (daoism/confucianism), middle way (buddhism), golden mean (aristotle), etc.

I've heard of wabi-sabi recently which seems like a similar idea in Japan.

I was going to ask, but I do now:

https://utopia.org/guide/lagom/