The supercharged XP bonus is actually fairly easy to acquire. All the player has to do, is skip a day's worth of daily challenges and log on a subsequent day. However, this doesn't provide as big of a boost as you would think. Fortnite has many ways to progress the battle pass: daily challenges, weekly quests, or just buying V-bucks to advance.
Supercharged XP is primarily used for those who don't want to be playing Fortnite every day but still want to complete their battle pass. The supercharged bonus accounts only for so much, allowing the player to earn up to the amount of XP they missed by skipping those daily challenges.
Utilizing the supercharged bonus is the optimal strategy for battle pass completion; it will save you significant game time in the long run.
There has been some confusion surrounding supercharged XP and double XP because they function similarly. Fortnite will occasionally host double XP weekends. Both XP bonuses double the XP you receive, but the supercharged bonus has the cap mentioned above to its gains where double XP weekends do not.
Speaking on in-game rewards and cosmetics, check out our coverage of the new cosmetics coming during the Fortnitemares event