Just signed up for this topic :)
I have a similar issue - something that fixes it for me, is I go to my VR desktop view in the Oculus App whilst the game is running (Whilst doing this, everything is on a go slow mode, even the tracking of my controllers) I hit ctrl+alt+del and open task manager, I then bring back DCS into focus and hit the oculus button to go back to game.
Once the above is done, my performance is back to silky smooth - I'd be interested in whether this works for you guys