You can easily expand .block>ul>li{Item $$}*4 to

<div class="block">
    <ul>
        <li>Item 01</li>
        <li>Item 02</li>
        <li>Item 03</li>
        <li>Item 04</li>
    </ul>
</div>

To do that, put your caret after an Emmet abbreviation and press Tab.

Wrap Selection is a re-work of original Emmet feature. It's using your editor instead of a prompt window. You can select any text, press Ctrl+Tab and type an abbreviation you want to wrap your text with.
For example, if you type .div>.article>.title, your text will be wrapped with:

<div class="div">
    <div class="article">
        <div class="title">{Your text}</div>
    </div>
</div>

Xemmet looks for {} in your abbreviation and it will put your text at this placeholder. If there's no such brackets, Xemmet will automatically add them the end of your abbreviation.

Xemmet supports custom snippets/abbreviations. To create them, open your profile folder, create the snippets.json file and read this article.

Xemmet provides different settings you can customize. You can find them under Editor - Smart Editing.