@KevinH: You are partially right. However, something has definitely changed.
This is particularly noticeable for people who use custom_preview_style.css (and custom_preview_style_alt.css) files.
In point 4 of your post, when you change the CSS, the custom_preview_style.css file suddenly stops being taken into account!
What's more, the "Cycle Custom CSS Files" button stops responding. In fact, it does respond to clicks, but this is not visible until we change the file in BookBrowser, for example.
I have a better way to demonstrate the problem.
1. Create a minimal
custom_preview_style.css, e.g., with one line:
Code:
:root {background-color: pink;}
2. Follow your post, but run "Inspect Page" and go to the "Sources”' tab.
3. When you get to step 4 and change the color to red, you will see what happens:
3a. custom_preview_style.css is ignored (there is no "file://" in Inspect Page) and no pink background
3b. the "Cycle Custom CSS Files" button will not respond.
Tested on the latest Sigil on Windows 10 Pro.