It was in response to some UX considerations for a feature I wanted to patch into vim. I must have had a bad week, I was needlessly combative after an initially abrasive response from another contributor who closed my issue without consideration. Bram stepped in and finally got the conversation moving.

We couldn't come to an agreement on how to implement it in the most robust way... meanwhile over at neovim a PR was submitted and merged, and a backwards-compatible solution provided within 3 days of me filing an issue. :-)