Toby You can set required = false
on the attribute and it'll be optional.
$configurator->tags['MENTION']->attributes['id']->required = false;
For the template, you can use a conditional that renders the mention as two different elements:
$configurator->tags['MENTION']->template =
'
';
Or you can render it as a a
element and use a conditional to create the href
attribute or not:
$configurator->tags['MENTION']->template =
'
#profile
';
I'll look into the img/alt attribute, that's got to be a bug. Edit: it was.