I am a skin creator that does commissions from time to time and a few of my clients have had problems using skins that are private or unlisted. Are you aware of any such problems with skins being set to anything other than public? I thought the only thing that was important is the workshop ID.
Unlisted, Private, and Public SKins
It's not a problem, it's by design. The 'client' paid for it, they can host it on their account.
well I doubt private workshop items can be downloaded by anyone because thats literally what private means and is, not sure about unlisted - i'd ask facepunch, nothing to do with the plugin