ColorCast v3.0 vs version 3.03

Ah, that’s right. I forgot about that sRGB message. That 3.0 version I’m recommending you use does not have the updates for newer operating systems that our newer versions have. This issue came up when Snow Leopard first came out. You can read all about it in this thread:
[one.imports.literateforums.com/t/10-6-and-the-colorsyncscripting-app/741/1)

Like it says, it does not affect the functionality of creating CC profiles, it will only affect how colors look on the screen while in ColorThink.

So for making the ColorCast profiles, you should use version 3.0.
For everything else, like viewing neutral rendering in the Profile Inspector, you should use the latest version (as of now that’s v. 3.0.3.) If version 3.0.3 is showing more variation from the L*, then so be it. It is surely more accurate than the 3.0 version. We’ve made a lot of changes since then. As I have duplicated your setup here, I find that the 3.0 version of the Profile Inspector is showing me the neutral line going all the way to 100%, even though the white point tab gives a lower white point. So something’s not right there.