CindyBolero has ported her “Winter Festival Aero Pines Park” content into Sine.space including a roller coaster. A bit more work is needed to sync up the views that each user sees. Apparently, sync on avatar movement is the default, but it is necessary to mark other region content such as a moving vehicle or coaster train that needs to be synced between clients.
Unity3D Asset Store steel roller coaster by Laxer…
https://www.assetstore.unity3d.com/en/#!/content/45897