Can a guest that is staying offsite participate in Extra Magic Hours.

No and Yes. What does that mean? Guests are required to tap their MagicBand to prove they are staying at a Walt Disney World hotel, Shades of Green, Swan and Dolphin Resort or Disney Springs hotel in order to enter the park for MORNING Extra Magic Hours.

The MagicBand is checked at the main entrance to a park for MORNING EMH. Once a guest enters the park for MORNING EMH, they aren't required to prove they are a resort guest. However, EVENING guests are only required to tap their MagicBand at the attractions when they wish to ride.