There is no way you want a "joint venture" with a major because that would dilute down the Explor interest in TPW - you want a "Direct Investment" into EXS by way of Private Placement. The major could throw two faces onto the Explor Board and they could set up a "TPW Budget Committee" in order to have a say in how the money gets spent.
If they take a stake in EXS directly, it means they like more than just TPW - it would validate the other exploration projects.