Ptah Dunbar

This plugin adds the ability to link to specific sidebars in the widgets admin page and have them open up automatically. In addition, by default when visiting the widgets admin page, none of the sidebars are open.
<pre><a href="<?php echo admin_url( 'widgets.php' ) .'?sidebar=aside'; ?>">Add Widgets</a></pre>
You’ll need to know the IDs of the sidebars you’d like to have opened. For multiple sidebars, simply separate them with commas.
<pre><a href="<?php echo admin_url( 'widgets.php' ) .'?sidebar=aside,body_open,before_the_loop'; ?>">Add Widgets</a></pre>
Alternatively, you can use the <code>add_widgets_link()</code> function:
<pre><?php echo waf_widgets_link( 'aside', 'Add Widgets to Aside' ); ?> <?php echo waf_widgets_link( 'aside,body_open,before_the_loop' ); ?></pre>

Widgets Admin Fix

This plugin adds the ability to link to specific sidebars in the widgets admin page and have them open up automatically.

FARAZFRANK

This is companion plugin is created for Avantex themes. 
The plugin add custom frontpage sections for Avantex themes and it will allow you full customizer settings for the theme front page sections. 
The plugin options are user-friendly and you can use this plugin for all avantex child themes also.
Have any queries?

Avantex Companion

tested up to 6.8 License: GPLv3 or later License URI: http://www.gnu.org/licenses/gpl-3.0.html Avantex Companion is a companion plugin for Avantex the …

Widgets Admin Fix vs Avantex Companion