I actually think it makes a big difference. The instructions you quote are pretty standard!
Journal names are handled by the term list settings and are usually headline style, while book titles and journal titles are set according to the title settings and often sentence style. So you just need to make sure your journal terms list is set up appropriately in your library (or libraries, if you use more than one).
see image for these two settings.
see here for the instructions on how to set up your journal terms list.
The bold and italics are set in the endnote output style’s bibliography templates for each ref type.
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