Basically as a user if I change the “Start at” in one scene and choose “Current scene” I would assume it would not impact the use of that in another scene.

For example if I shoot a scene and then using forward slash break it into smaller scenes. Then I go to one of those scenes and click the layer like in the screenshot “step 1” (the bottom layer so maybe that is the issue) and then change the start at for “Current Scene” it ends up shifting the video on the scenes before and after it that are part of all the scenes that came from it.

I would except current scene to not impact any other scenes.

BTW Support noted this:

The "Start At" option is actually a layer property, which means that it impacts the start time of the full clip. It's similar to our Slip tool, which will shift the visible portion of video inside a fixed-duration clip, without changing its position or length.