'skip navigation' button should become visible when it has focus

[moloko]

At least, according to the page about this accessibility feature in Techniques for WCAG 2.0:

Check that the link is either always visible or visible when it has keyboard focus

I'm sure at one point it did display when it had focus but this functionality seems to have been lost/changed at some point.

[moloko]

Also just to note it has a class a11y-ignore-focus attached to it but I can only find one other reference to this, here:

adapt_framework/src/core/js/helpers.js

Lines 326 to 330 in 5a3de69

	a11y_wrap_focus() {
	const cfg = Adapt.config.get('_accessibility');
	if (cfg._isPopupWrapFocusEnabled === false) return '';
	return new Handlebars.SafeString('<a class="a11y-focusguard a11y-ignore a11y-ignore-focus" role="presentation">&nbsp;</a>');
	},

Is this something 'legacy' that needs to be removed?