$(window).trigger('resize'); on line 226 of wp-slabtext.php solves the problem that appears when the page loads and you have a fixed width on the container of your slabtext. The text renders 100% of your screen width even when you have a set width on the wrapping container. Once you resize the browser the script kicks in and it resizes to the correct size but not on page load.
New line 226
$webf_script .= "$('.".esc_html($parents_class)."').slabText(); $(window).trigger('resize');";