@anonymous_user_439f45e8 The difference is that your BP is a derivative work, literally. You took someone else’s work and improved it. The license doesn’t allow it to be re-sold.
If you wanted to sell your footprints BP, you should have created your BP from scratch. Then you could have sold it without any issues.
It’s like if someone makes a 3D model of some creature (let’s say Chimera), releases it on the Marketplace. If I buy it and see it is poorly optimized, looks ugly (in my opinion), etc. etc. I would simply make a new model of Chimera, (the way I see it fit) and then I can release it. Even if it resembles Chimera that was already on the marketplace, I would have no issues with legality of my actions.