I haven’t quite understood the point yet.
When I post a link, there is a placeholder and a click leads to the underlying link.
Or would you like to post the link of your page in such a way that the page is displayed there as iframe? I also have to say that this is the first time I stumble across this parameter ?embed=true.
If I read the right one, use the Url parameter like this: ?:embed=yes
and as far as I know this is set as url parameter for the iframe tag – this way ( but than code in a posting must be activated and allowed
<iframe src="https://guenterweber.com?:embed=yes"></iframe>

my definitive advice – take the little magnifying glass icon instead.

the most easiest way would be to register a new social media button for example with a lock and have the rounded buttons as if it was a social media link – on hovering you can see the tooltip : registering.
i do this often for links like intranet link or login links.
this could be handeled than like on my link above – because than it is part of social-media list.

See here Result ( i do not change to see only burger-menu – so have a look at smaller screensizes )
https://webers-testseite.de/cynthia/

if you like to insert for example a whole avia button shortcode – that is possible too.

add_action('ava_inside_main_menu', function() {
  echo '<li class="registerbutton">';
  echo do_shortcode("[av_button label='Register now' link='manually,#' link_target='' size='large' position='left' label_display='' icon_select='yes-right-icon' icon_hover='aviaTBicon_hover' icon='ue875' font='entypo-fontello' color='custom' custom_bg='#42ab96' custom_font='#ffffff' av_uid='av-b9l' custom_class='' admin_preview_bg='']");
  echo '</li>';
});

function change_menu_position() { 
?>
<script>
(function($){
	$('.main_menu ul.social_bookmarks').insertBefore($('.main_menu div.avia-menu'));
	$('li.registerbutton').appendTo('.main_menu > .social_bookmarks');
})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'change_menu_position');

the code can be obtained by activation of the debug mode on enfold for above rules
– echo do_shortcode(" into this comes the full shortcode of your avia button ");

this comes to quick css:

/*** this is for the new button not to have same behavior as social_bookmarks buttons ***/
.registerbutton { width: auto !important }
.registerbutton .avia_button_icon { display: inline-table }
.social_bookmarks li.registerbutton a { border-radius: 0 !important; padding: 0 10px !important; width: auto !important; background: #42ab96; color: #fff }

/*** rules for the left-hand social_bookmarks buttons ***/
#top nav .social_bookmarks { margin-top: -20px !important; overflow: visible !important; height: 40px !important }
.avia-menu.av_menu_icon_beside { padding-right: 0; margin-right: 0; border-right-width: 0; border-right-style: none }
.social_bookmarks li a { height: 40px !important; line-height: 40px !important; width: 40px !important }
#top .social_bookmarks li { width: 40px; height: auto !important }
#top .av-logo-container .social_bookmarks li a {  border-radius: 50% }
.av_header_transparency .social_bookmarks li a { color: #969696 !important;}

for the hamburger menu : doesn’t he like to have the current page highlighted in red?

#av-burger-menu-ul :not(.active-parent-item) .current-menu-item > a .avia-menu-text {
    color: red !important;
}

better if the image can be masked then use a png image in a color-section with no padding ! Do not use the sligthly increase the image on hover option, because i want that only the image got the hover increase.
give the color-section a gradient background. to have the image on the bottom of the color-section and to have no overlay on hovering do this to quick css:
(adjust the page/post to your givings – be careful the avia_transform class is a html class)

.avia_transform .postid-32650 a:hover .image-overlay {
  display: none !important;
}

.postid-32650 a.avia_image.lightbox-added img {
    transition: all 1s ease-in-out;
}

.postid-32650 a.avia_image.lightbox-added:hover img {
    -webkit-transform: scale(1.1);
    transform: scale(1.1);
    transition: all 1s ease-in-out;
}

see result here: https://webers-testseite.de/huawei-2/

i thought he/she likes to replace the default h3 Iconbox title to a h2 title. – but i can not see the hidden private content – maybe there is more info on this.

to change all captions from h2 to h1 put this into your functions.php of your child-theme:

function replace_tags_with_tags(){
?>
<script>
  (function($) {       
      function replaceElementTag(targetSelector, newTagString) {
        $(targetSelector).each(function(){
          var newElem = $(newTagString, {html: $(this).html()});
          $.each(this.attributes, function() {
            newElem.attr(this.name, this.value);
          });
          $(this).replaceWith(newElem);
        });
      }
      replaceElementTag('.slideshow_caption h2.avia-caption-title', '<h1></h1>');
  }(jQuery)); 
</script>
<?php
}
add_action('wp_footer', 'replace_tags_with_tags');

read carefully on top of this page – it works with child-theme and edited Alb Elements:
https://webers-testseite.de/edited-enfold-alb-elements/#icons

or if you only want that for all icon-box titles instead of h3 a h2 – put this to functions.php of your child-theme

function replace_tags_with_tags(){
?>
<script>
  (function($) {       
      function replaceElementTag(targetSelector, newTagString) {
        $(targetSelector).each(function(){
          var newElem = $(newTagString, {html: $(this).html()});
          $.each(this.attributes, function() {
            newElem.attr(this.name, this.value);
          });
          $(this).replaceWith(newElem);
        });
      }
    
       replaceElementTag('h3.iconbox_content_title', '<h2></h2>');  //you can add here more tag replacements 
      
  }(jQuery)); 
</script>
<?php
}
add_action('wp_footer', 'replace_tags_with_tags');

don’t know – he has opend a new thread – but my solution with selfhosted video works !

on this case : If you want simple solutions, you have to be satisfied with simple requirements.

on Avia Layout Builder take a color-section.
Open that color section options dialog – click to the section background and set your wanted image.
Set your image behavior here too- if you like to repeat the background or if it is stretched. (on your example it seems to cover the element)
Set the image as you like to behave : scroll, parallax or fixed ( all will leave the screen on scrolling but with different effects)
Goto the tab on top : Section Background Overlay – set your overlay color if wanted – on your example it seems to be a black overlay color with f.e. 0.5 opacity.
Thats all – you can drag all you wanted into the color section now

i do allways this code to functions.php of my child-theme – it deactivates the reset all button too:

function admin_head_mod() {
echo '<style type="text/css">
#avia_quick_css .avia_description {float: none;margin-bottom: 20px !important;padding-left: 0 !important;width: 98%}
#avia_quick_css .avia_control {float: left;max-width: 98% !important;width: 98% !important}
.avia_footer_links li {float: left;padding-right: 20px}
.avia_footer .avia_footer_save {float: left}
.avia_reset {pointer-events: none !important }
</style>';
}
add_action('admin_head', 'admin_head_mod');

you are always welcome
and even if English is not my native language, I am probably understood, even if my sentence constructions are easily recognizable as German.

can you try this in your functions.php of your child-theme:
this filter you will only need if you havn’t got a secondary menu or social media – so there will be no header-meta
add_filter( 'avf_execute_avia_meta_header', '__return_true', 10, 1);

for you this will be enough i think:

add_filter( 'avia_meta_header', 'avia_append_search_nav_mod');
function avia_append_search_nav_mod()
{
          global $avia_config;
          ob_start();
          get_search_form();
          $form =  htmlspecialchars(ob_get_clean()) ;

          $items .= '<li id="menu-item-search" class="noMobile menu-item menu-item-search-dropdown menu-item-avia-special">
                        <a href="?s=" data-avia-search-tooltip="'.$form.'" '.av_icon_string('search').'>
                          <span class="avia_hidden_link_text">'.__('Search','avia_framework').'</span>
                        </a>
                    </li>';

    echo $items;
}

Edit: i see it has on header meta a list-point so add this to your quick css:

#top #menu-item-search {
    list-style: none;
}

please delete your comment on this rule:
// Full Width on Mobile for Blog Featured Images and Videos

because on css you comment things by: /**** comment ***/

the method by //comment is used in php files