> This is very useful for colorscheme developers

I would posit then that this article simply doesn't apply to you at all. The feature being described is targetted at users who are effectively developing their own schemes (albeit in a rather simplified automated manner). If I'm taking something off the shelf, I'm using the appropriate recommended base16. I have no expectation that a wild base16 is going to align with any 3rd-party's curated scheme.

I do understand that this logic isn't always going to click with people given the differing contexts of a terminal-wide -vs- app-specific (i.e. vim) approach, but again: that disparity seems either a legacy issue (caused by things like this 16-256 mis-alignment) OR simply a philosophical difference (whereby people who customise at the term level shouldn't at the app level & vice-versa).