Entity Registration: Override built-in registration list with custom view
In case someone is interested, I came up with a very nice and simple solution. I'm implementing hook_menu_alter() and overriding tab's "page callback" so that my custom view is called instead built-in registration list. (Note that solution below covers only tab for NODE entity!)

function MYMODULE_menu_alter(&amp;$items){
    $items['node/%entity_object/registrations']['page callback'] = 'regstrations_view';
}

function regstrations_view(){
    $node = node_load(arg(1));
    return views_embed_view('my_registration_list_view','page', $node-&gt;nid); 
}