If someone gets up early and puts on his tallis kattan (at the right time) knowing that about an hour or 2 latter he’ll be putting on his tallis. Can he make a bracha on his tallis kattan earlier, or does he have to wait untill he’s yozei with his tallis? Is it a bracha levatalah?
The ordinary custom is to wait until wearing the tallis gadol, even for someone who will be waiting a lengthy period of time.
However, making a berachah on the tallis katan would not be a berachah levatalah.