Add a sidebar to the Memberlite blog and archives pages when using the grid-style post layout.

memberlite_modify_columns_ratio_for_blog.php

<?php
function memberlite_modify_columns_ratio_for_blog( $r, $location ) {
    // Check if the current page is a blog page
    $maybe_add_sidebar = memberlite_is_blog();

	if ( $maybe_add_sidebar && ! in_array( $location, array( 'header-right', 'header-left' ) ) ) {
        // Set layout ratio for the blog main area and sidebar
        $r = ( $location == 'sidebar' ) ? '4' : '8';
    }

	return $r;
}
add_filter( 'memberlite_columns_ratio', 'memberlite_modify_columns_ratio_for_blog', 15, 2 );