Answered: Platform Lip On Upper Surface.

While constructing a replica platform for practice and testing, I realized that sources were inconsistent when it came to whether the platform had a “lip” on the edges or not, as shown below:

Does the top of the platform have a lip before it or is it set inside the ramp?

The platform has a “lip” as shown in the bottom picture of your post.
What are the “inconsistent sources” you are referring to? I’d like to make them consistent.