I think there may be some confusion with the terminology. "Tail feathers" could mean the control surfaces or the entire empennage. Are you saying that you have your rudder attached to the vertical stabilizer and the elevators attached to the horizontal stabilizer? If that's the case, then I would leave them that way for now, tucked safely away in a corner of the hangar. But you're going to want to break those assemblies apart before you mount the HS and the VS to the fuselage. Regardless of how much space you have, you don't want the rudder or the elevators to be able to flop around while you're trying to get things aligned and dialed in. That's inviting damage. Not to mention that it's a little heavier when you're moving completed assemblies around. It won't be the only piece that you assemble and disassemble during the build. Trust me. As another post said, it's just a few bolts.
Further down the road when the fuselage is complete, many builders fit & drill the HS and VS to the fuselage, then remove the empennage components again to free up room in the shop or. It also makes transporting the plane from your shop/house to the airport easier. If you have a big space you're currently working in, that may not be necessary and you could leave the entire empennage mounted.