Eevee Reflection Plane Question

I'm seeing what I think might be errors in how the reflection plane probe renders in 2.8 beta Eevee. In the 2-frame GIF image (linked below), I have a reflection plane probe placed just above a geometry plane with reflective material. Three spheres float above, and a single HDRI world illuminates the scene. You may need to click the link to see the image, I'm still learning the markdown syntax here. The thumbnail only shows the first frame.

I'm noticing that, with ScreenSpaceReflections OFF, the reflection of the spheres appears "multiplied" or "screened" onto the reflection of the world. I would expect the spheres to appear opaque in the reflection and not show any world through themselves.

When ScreenSpaceReflections are ON, the spheres now appear opaque as expected, with no world showing through them. However, the world reflection has now shifted slightly. This also seems strange -- I would expect the world to appear basically the same in either case. Another oddity is that the spheres in this case have ghosts of themselves smeared off to screen right. This may be due to the imperfect nature of SSRs, but here it seems like the approximation would be a lot closer.

If others feel this isn't correct behavior, I will submit a bug. Please comment if you have any thoughts. Thank you.

![EeveeReflectionPlaneTest] Link