When can I add Xtra Boosts to my entry? When you're almost finished with your entry, then you'll have an opportunity to apply Xtra Boosts. Related articles Contact Us How many Xtra Boosts can I use? I joined FLX Rewards at Champs Sports. May I still use my benefits at Foot Locker? I forgot to tell a store team member I’m an FLX Rewards member. Can I still get points for my purchase? If I create two accounts, then can I combine them?