echo '<div class="sclogin-modal-links sclogin"><a href="#login-modal" role="button" data-toggle="modal">'.JText::_('MOD_SCLOGIN_LOGIN').'</a>';
echo ' / <a href="' . $registerLink . '">'.JText::_('MOD_SCLOGIN_REGISTER_FOR_THIS_SITE').'</a>';
Yup, looks like we missed those strings in the template files. Sorry for the inconvenience. The updates to use the language files for those strings will definitely be in an upcoming release. We already have a planned update for later this week (v3.0.2), and I'm not sure if this change will make it in that release since it's already in testing. It should definitely be in the 3.1.0 release that will likely be out later in July.
Thanks again for the feedback, and we hope you like the SCLogin module overall,