"Render Bump Map" Help me with Transparent-to-White versus Black-to-White gradient use by AE effects

AE 2025.2.2 (build 2)
When does an AE effect generate either Transparent-to-White or Black-to-White bump maps?

I followed a YouTube tutorial using CC Ripple Pulse. The video host activated "Render Bump Map" and his gradient went from Black (-100) to White (+100). On my PC, the gradient goes from Transparent (-100) to White (+100). I'm feeding the generated bump map into CC Glass, which uses a Black to White gradient.

I fixed my issue by placing a Solid Composite effect below the CC Ripple Pulse effect and set the color to Black (00 00 00). Now the comp generates the full black-to-white gradient which is being used by the adjustment layer comp that has the CC Glass effect.

My assumption is that the entire project is using a media render that does not use Black in its Alpha channel, or it doesn't have an Alpha channel at all. I'd like to know where that setting resides.