Hi
let me reiterate. The issue is not the lexical-binding t or nil.
The issue is "buffer variables" vs "convention of 'name --- description'.
TRT is to "fix" checkdoc to look for the
'name --- description' within the first (10) lines, AND/OR to revert to the old convention of having the '-*- ... -*-' line(s) within the first 10.
Once that is done, the documentation can be amended accordingly, relaxing the mandate that the first line MUST start with ;;; foo --- bar. and no extra update in any files will be needed.
All the best
MA