Re: Proposal to change documentation on tabindex to strongly discourage values greater 0

+1 for strong advice against tabindex > 0 and a (only slightly cautious) +1
to consider it invalid behavior.

The reasoning for considering it invalid:

In all cases, tabindex="more than 0" permanently changes the logical,
navigable flow of the page without informing the user. That is, unless you
are redirecting focus via javascript. BUT since this would require using
the focus() method with deliberation anyway, why would you use tabindex="1"
when you could (and should) use tabindex="-1" or just focus an implicitly
focusable element??

There is absolutely no need for positive integer tabindexes and I've only
ever seen them used for harm (unintentionally in most cases). This feature
should be consigned to the pile where all the presentational attributes
reside.