As a sample upload separate stems should be standard. Otherwise it’s a mixed track, which we are explicitly asked not to upload as samples on the sample upload page. You can always upload the mixed track as the preview accompanying the stems. That way people have the mixed track if they want a ‘starter’ and the stems if they want to remix. In other words - of course we want the stems, don’t make us ask. You have excellent material to share and this mixer thanks you.