Lumen is really dependent on the number of lights that are visible at any one time. I did some tests in the early access version, and you can usually maintain 100+ fps in VR with a maximum of four visible lights at a time. Obviously, the type of lights and your lumen settings will affect this. Controlling the amount of rays cast, etc will improve performance.
Note that it doesn’t matter how many lights in are actually in the scene. I put 50 rect lights off in the distance, it didn’t affect performance at all as long as I didn’t go over to them. So if you’re doing an interior or something, you can have numerous lights as long as they’re spaced out properly.