Plugins - How to manipulate the Category of a Mentionable content item?

Hi all,

I created a new content type that is searchable, peekable, and mentionable.  In addition, this content type has no UI components and represents resources that lie outside of the community.

My only issue is that when someone @mentions it in the editor it shows up under the "Content" category in the popup, which isn't ideal.

My goal is to show the mentionable items of this new content type under it's own category Category name in the @mention pop-up, so that those items are separated from "Content" and "Members".

I've dug into it a bit and found that the Category names are fed to the UI from the response to a XHR call to the server.  This is the URL that gets called (I broke the URL down into components for easier reading).

https://socialedgeconsulting.io/tinymce/apis/mentions?
_pcurl=~%2Frob-sandbox%2Fb%2Fblog%2Farchive%2F2023%2F03%2F10%2Ftest%2Fedit
&t=s
&query=blue
&contenttypeid=f7d226ab-d59f-475c-9d22-4a79e3f0ec07

And this in turn returns JSON data that looks like this.

{
    "categories":
    [
        {
            "label": "Content",
            "mentionables":
            [
                {
                    "contentid": "d7360fa1d3f14daea02ce1ade4157774",
                    "contenttypeid": "ab24fe3ffdf24720a8036645b01e3519",
                    "previewhtml": "...",
                    "defaulthtml": "...",
                    "supportslabelhtml": true,
                    "isrecommended": false,
                    "detail": "...",
                    "url": "..."
                },
                ...more...
            ]
        }
    ]
}

 I reviewed the IMentionableContentType interface, which accesses an Enumeration of IContent objects, but none of those containers appear to have a "Category" property, so I'm not sure why the code is categorizing these as Content items or if there is a way to define a custom Category name.

Any thoughts on this would be appreciated.