Thank you Usicco, it works !
Turns out I had everything fine but I was not using the injector properly. You must have SteamVR down before using the drag and drop on the injector. I didnt know that
Unfortunatly it doesnt work for me tried on 5.2 and 5.4 with injector 0.8 now and the yiff log file says
Initialize engine version: 5.3.4f1 (fdbb5133b820)[VRDevice] Initialization of device oculus failed.
and it starts in 2D.
Did I mis somethin…