A simple bit of HTML that you could re-use, inserted at the top of any new article, eg:

<div class="key-points">
    <h3>Key Points</h3>
    <ul>
        <li>Point 1</li>
        <li>Point 2</li>
        <li>Point 3</li>
    </ul>
</div>

You can style it using a css rule in your template stylesheet:

.key-points {
    border: 1px solid red;
    padding: 5px;
    width: 100%;
}

Since this going to have to be done for every article past and present, is there a way to build a "shortcut" button so to add this HTML each time and/or without having to switch to HTML mode in JCE?

Add the Template Manager button to the editor toolbar, with the Key Points code already added to the editor content, click the Template Manager button to open it.

Click the New Template button to open the Text Editor, and click the Save button in the bottom right corner. Name the file and click Save, then close the Text Editor window.

Close the Template Manager.

Refresh the page.

Click on the dropdown arrow on the Template Manager button, and select the new file you have created. This will insert the html content into the editor at the cursor position.