Change layout of Tag Page

I found this article in the support on how to change the archive page layout to “blog-grid”. Here is the link to the article:
https://kriesi.at/support/topic/archive-page-layout-changes/

I added the code from the article:

add_filter('avf_blog_style','avia_change_tag_blog_layout', 10, 2); 
function avia_change_tag_blog_layout($layout, $context){
if($context == 'tag') $layout = 'blog-grid';
return $layout;}

But need to change the $layout to ‘single-small’. So I created this filter:

add_filter('avf_blog_style','avia_change_tag_blog_layout', 10, 2); 
function avia_change_tag_blog_layout($layout, $context){
if($context == 'tag') $layout = 'single-small';
return $layout;
}

But it still shows the entire article. I want the content to be excerpt – read more only. Can someone assist with the needed code. I think I have it 90% there.