Agreed, do not seal maple, use hardware store stain, or fillers. The Birchwood Casey stuff is for walnut. IF you use any of the previously mentioned, you will have an unstainable white stock. It will look terrible.
Maple is different than many woods. Start with ferric nitrate stain, adjust with dye stains, finish only when I looks like you want wetted with mineral spirits. Maple is nonporous and does not need any fillers. Never apply finish hoping it will look better after. Once you apply finish you burn bridges.