The option for one-click-login is availible, but for what i see in the canidate release, its not build to open in an new tab.
add a new form:
|*if HAVE_ONE_CLICK_PMA_LOGIN="yes"|
<br>
<form id='pma_form' action='CMD_PMA_LOGIN' method='POST'>
<input type='hidden' name='name' value='|name|'>
<input type='hidden' name='domain' value='|DOMAIN|'>
<input type="submit" value="phpMyAdmin SSO"> Login, no password required.
</form>
|*endif|