I know this has been mentioned elsewhere on several occasions (reddit, etc)
However, I thought it was worth bringing more attention to it since it has yet to be fixed (people get really frustrated playing UE4 games)
The VR motion controllers in UE4 set whichever one was turned on first to left and don’t always match the Left and Right controllers in SteamVR - this is a nuisance for a lot of people playing other games who then start playing a UE4 game and have to take off the wrist straps, swap hands, and put the wrist straps back on or power cycle the controllers.
Left/Right orientation should match that of SteamVR rather than setting the first one turned on to left.