can shr-start go away?

[Mike Kupfer <kupfer@rawbw.com>]

shr.el has

  (defvar shr-start nil)

But the only place in Emacs that checks the value of shr-start is
shr-tag-a, and shr-tag-a overrides the defvar via a "let" declaration.
shr-tag-img can set shr-start, but it doesn't use shr-start itself.

Am I missing something?  (I'm still something of a Lisp newbie.)

If shr-start can indeed go away, I can do that as part of the fix for
bug#60423.

thanks,
mike