[ska]

Am I missing something?

In "regular" Reyes (and I may just have this wrong - I was unaware that the hybrid technique you describe was common) I though you were a) locally approximating surfaces and b) applying local shaders. These shaders are typically inferior estimates of the BSDF at that location compared to other techniques, but can be very memory efficient.

In the hybrid approach you describe, you avoid at least (b) above by doing the shaders by path tracing, say, but localized to where your rasterizer has discovered. So you aren't benefiting in anything but speed, so this seem more an implementation detail than anything fundamental.

So I don't see how dropping this sort of detail from any introductory course is anything but sensible. There should probably be a discussion of space/speed/distributional issues in general, but at a higher level.

Again, I'm not questioning why anyone would want to implement it, just why anyone would find it odd to leave out from an introductory course.