Magazine blog layout: Excerpt & larger thumbnail

We are using the magazine blog layout, but we want an excerpt to show for all of the posts. I have seen this thread:
https://kriesi.at/support/topic/show-excerpt-in-all-magazine-blog-list/, but it’s over a year old, and the solution was changing code in one of the core files of the theme which isn’t good practice (because it would be overridden in an update, right?). Is there a way to show the excerpt within the Enfold settings without creating a child theme or changing the theme files?

Also is there a way within the Enfold settings to change default thumbnail size for the magazine layout? I have searched through the Enfold settings for both, and searched through the tutorials and documentation but I couldn’t find anything.

Thanks