In new update you can add unlimited mod varaint. When you add Varaint name and mod file or link it show like that in image. If you uploade file it's show "Download" button & if you give link it's show "Click Here" button.
You can upload multiple file & add multiple link in one post. There have option to add multiple mod file and link. Even you can add file & link is same time without face any problem
You can see this section is post page. To add mod variant click "Add New Variant" button. Then you can add multipal variant. There have no limited, So you add unlimited variant by click the "Add New Variant" button. You can't able to to add file & link in a same mod variant. If add file then can't add link or if you add link then you can't add file in a same mod variant. There are all upload file storage are FREE