Luckily, of course, it's open source, so I just added the options I needed.
https://github.com/torstenvl/betterls if anyone is interested
exa seemed like overkill for my needs, and it was easier to add a couple lines of code than to learn a whole new tool.
There might be enough other new functionality such as abbreviation or multi-attribute colorization schemes to motivate learning a new tool. E.g., neither "dot-ness" nor "directory-ness" in the above is hard-coded. They could be any other convenient elements of the typology / taxonomy.
I specifically wanted to stay close to stock because macOS `ls` is designed for the system it runs on. Installing coreutils would be counterproductive.
alias ls='LC_COLLATE=C \ls -F'