I'm currently a class teacher and I also teach PE to my students.
I'm constantly using WBT, even in PE.
I have to say that it's a little harder in PE than in the classroom, but just because it's a little harder to carry the scoreboard than in class. For all the other things, it is exactly the same.
Yes, your voice suffers a little more because when kids are physically involved in games and so on, you have to rise your voice higher than in class, but with class/yes it's not that big issue, you only need to "shout" class.
Best,
Edward