Hey Guys! I wrote a little fix for this issue. In \wp-content\plugins\woocommerce-super-simple-tax-exemption\js\taxexempt.js, the entire file should look like this:
jQuery(document).ready(function($) {
$('#tax_exempt_id_field').hide();
$('#tax_exempt_checkbox').on('click', function (event) {
$('#tax_exempt_id_field').slideDown('slow');
$( 'body' ).trigger( 'update_checkout' );
});
$('#tax_exempt_id').on('change', function (event) {
$( 'body' ).trigger( 'update_checkout' );
});
});
This should make it so that if the checkbox is unchecked, or the tax exempt id is entered, the cart total updates. Enjoy!