Can the final consumer prevent geese from possible suffering by purchasing quilts filled with other filling material than down and feathers?

Everyone can buy the quilt as one pleases. However, if you decide not to purchase a down quilt, it will not have an effect on the down supply. Unavoidably, down is a by-product of the meat production. If poultrymeat continues to be most popular with the consumers, the down supply will remain unchanged. The remaining down would be thrown away and the demand and the prices of the resources for the production of other filling materials would probably increase.