If you’re blending or processing the duxelles, it would just be a case of blending it a little extra to help with the structural integrity? If you’re still havering structural integrity problems, either sub in French Onion Soup Powder for the onions or leave them out (you’ll get oniony flavour from the duxelles)
I’d say keep the red wine, it’s not an uncommon thing to have in a burger anyway, and it would stop the party being too dry. If it’s too wet, add breadcrumbs!