Yes it's Xenia. There are many types. That looks like Pom Pom Xenia to me.
Yes, most Xenia spreads quickly. But you can keep it on its own little rock island. It will have a very difficult time spreading across sand and can simply be clipped. It may drop pieces, which should be removed before they attach elsewhere. If you put any such pieces in a shallow tray of rock rubble, you can give them away as frags.
Someone stop me! Please! But... not just yet...
55 Gal Tropical FW
55 Gal Mixed Reef