I like what you've done with it, I'll need to take a closer look.
While I was thinking about it, I also decided to take a look into prior art, which took me all the way back to Landin's "The Next 700 Programming Languages" from 1966 which introduced the hypothetical language ISWIM, which was the first to introduce indentation based syntax and inspired the ML and Haskell family of languages (https://www.cs.cmu.edu/~crary/819-f09/Landin66.pdf)
It wasn't exactly what I was looking for, but it's fascinating to see how long we've been thinking about these kinds of issues.