The Founder’s Exchange is an in-game store which will have the cosmetic items listed in the Kickstarter where you can redeem your Founder's Points. You can also put them toward an upgrade in the online store now if you so choose. . Founder's can expect to spend their points either close or during the full release of the game.
The Exchange is a great way for Camelot Unchained backers to customize their reward tiers. Once the “funding drive” for the game ends, backers will not be able to buy additional Founder’s Points. The FE will stay open to allow backers to redeem the points they received during the funding drive but the developers will not add the option to buy additional points.