Hello! So to answer your question in short: no, this is not exactly possible. There is maximum crispness at what we refer to as the focal or convergence plane – that is because at that point in space, all views being rendered are exactly the same. It’s effectively the same as rendering it in just 2D. That also works in reverse – if something were rendered with all the views the same for the sake of crispness, in 3D it would look like it appears flat in the middle of the focal plane. You could then place objects in front of it, closer to the viewer, but anything placed behind would create a brain-breaking scene of impossible dimensionality.
One option you might consider is using the custom FOV option. You can find it in the inspector on the HoloPlay Capture object under Capture > Advanced. Increasing the FOV can produce the effect of having the background seem further away but also more crisp at the same time.