Here's an idea: Why don't you see if you can set up a plug-in system so that your users could purchase and use Swift's seamless texture algorithm. You could provide a free one for free, but make it possible to upgrade to Swift's excellent system.
PW3D is being developed on top of the BlitzScript3D Engine and BlitzPlayLite to support a Updateable Plug-in Management System via the internet. Additionally the source for PW3D is available. So it will be very possible for users to integrate Swift's excellent system. However, I would like to provide a default solution and the source will be available others improve upon it.