I suspect it's because the new SMuFL fonts have so many characters (most of which the majority of users will never use) it's just not practical to list them.

Take a look at PopChars X from ergonis.com

HI Richard, there are character sets for the legacy fonts in the manual, but you are correct that the same is not true for the SMuFL-based fonts. As Mike mentioned, part of the decision to not add these glyph charts to the manual was because of the amount of characters in each font.

The major factor though was that our SMuFL fonts (like other SMuFL fonts) adhere to the SMuFL guidelines for glyph code point location in the font. This is a standardized aspect of the font, so in the user manual here we have a link to this location at the W3C's standards page where you can search for the locations of the characters you need .  

The other option for finding characters is using the search field in the updated Symbol Selection dialog box. Here, you can simply type in the name of the character you want, and the search field will help narrow down the location of this for you. I hope that helps answer your question.

Hey David…..

I appreciate you taking time to explain. I guess I have a lot to learn about the SMuFL fonts. Thanks for pointing me in the right direction. 

And thanks for the recommendation, Mike. PopChars X looks to be way more capable than FontBook. 👍🏻