In the text format configuration area, We have a single giant text area for providing allowed CSS classes and their human-readable labels:

The description text for this textarea is as follows:
A list of classes that will be provided in the "Styles" dropdown. Enter one class on each line in the format: element.class|Label. Example: h1.title|Title.
Each style should be in your theme's main CSS as well as in your theme's ckeditor-iframe.css file.
Though it's possible to read all that text and get the data entered into here correctly, we could make it a lot easier on our admins if we provided a key/value entry system like we do for field values.
We might even be able to use an options-element since both text areas use the vertical pipe as separator.
Recent comments
@yorkshirepudding thank you for the additional info on improving discoverability and a handy way to keep a list of projects for reuse.
Why not add a Github star?
It is a good point @izmeez and when I was researching repo discoverability I found that GitHub search does prioritise matches with more stars. This is what I was researching for:...
Why not add a Github star?
Do you have a separate development environment and transfer database and config between sites?
Wierd happenings regarding updates...