Hello Jason,
To my knowledge, once you customize the configuration, you also need to set all other settings yourself in the config file. (if there are other ways, then I just don't know yet). So if you are ok with customizing all your options then here's how:
1. In your module, double click on the 'Config' property for the CKEditor
2. Copy paste the config information from the Demo module available in the Forge (or from another source if you have one). For your convenience I am sharing my version of the Config settings so you can customize it as you wish:
"toolbarGroups: [
{ name: 'document', groups: [ 'mode', 'document', 'doctools' ] },
{ name: 'clipboard', groups: [ 'clipboard', 'undo' ] },
{ name: 'editing', groups: [ 'find', 'selection', 'spellchecker', 'editing' ] },
{ name: 'forms', groups: [ 'forms' ] },
{ name: 'basicstyles', groups: [ 'basicstyles', 'cleanup' ] },
{ name: 'paragraph', groups: [ 'list', 'indent', 'blocks', 'align', 'bidi', 'paragraph' ] },
{ name: 'links', groups: [ 'links' ] },
{ name: 'insert', groups: [ 'insert' ] },
'/',
{ name: 'styles', groups: [ 'styles' ] },
{ name: 'fonts', groups: [ 'fonts' ] },
{ name: 'fonts-size', groups: [ 'fonts-size' ] },
{ name: 'colors', groups: [ 'colors' ] },
{ name: 'tools', groups: [ 'tools' ] },
{ name: 'others', groups: [ 'others' ] },
{ name: 'about', groups: [ 'about' ] }
],
removeButtons: 'Iframe,ShowBlocks',
extraPlugins: 'wordcount,notification,font,colorbutton',
wordcount: {
showParagraphs: true,
showWordCount: true,
showCharCount: true,
countSpacesAsChars: true,
countHTML: false,
maxWordCount: -1,
maxCharCount: -1
},
disableNativeSpellChecker: false,
scayt_autoStartup: true
"
3. The last 2 lines of code above will enable spell check for you on load. These 2 lines of code work well together for me. Based on your own browser settings, sometimes just one of them may do the trick.
4. Publish and run. Spell check is enabled!
Note: Typically it takes 2 - 3 seconds for the red lines to display.

I hope this solves it,
Regards,
AJ