StylesSet configuration is broken

In the versions below 1.60, it was possible to configure the stylesSet item from the WYSIWYG Editor -> Advanced Configuration, as per CKEditor documentation (https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR_config.html#cfg-stylesSet)

SInce 1.60, the following instructions do not have any effect when configured in the Advanced Configuration section:

// Do not load any file. The styles set is empty.
config.stylesSet = false;
OR 
// Load from a list of definitions.
config.stylesSet = [
    { name: 'Strong Emphasis', element: 'strong' },
    { name: 'Emphasis', element: 'em' }
]

I understand there may be a different way to achieve this but I didn't find one in the documentation and it breaks existing configurations.

Seems to be related to https://github.com/xwiki-contrib/application-ckeditor/commit/bfdbebb998d0c8aeb0bce3e28f5b2e6e21e588f7#diff-473e1cd6b21b9bc72472c03245f2c3a9ed4b352e5bb00348f991960d0f7f0087L29.