SSRR pass 0 stops at 100 units

We are seeing in both our production environment and a simple test case that screen space reflections have some sort of hard clip plane at 100 units from the camera.

Our game has something of an isometric view (perspective camera), and this clip plane expresses itself in an obvious fashion around 2/3rds up the screen.

We scoured over the source code and couldn't find any obvious places this 100 unit limit exists.

Can anyone from Unity explain to us what we're seeing and how we can over come it?

Attached is a screen shot from the simple test case, paused in the frame debugger, showing the results of pass 0 of SSRR. Every pass after this is masked by this clip.