We recently had a customer using the Supply theme in Shopify, who needed a hand getting Ajax cart recommendations working.
We edited snippets/ajax-cart.template.liquid and added the parts below in bold to the drawerTemplate
<script id="drawerTemplate" type="text/template">
{% raw %}
<div id="ajaxifyDrawer" class="ajaxify-drawer">
<div id="ajaxifyCart" class="ajaxifyCart--content {{wrapperClass}}" style="margin-bottom: -225px; padding-bottom: 249px;"> </div>
{% endraw %}
{% include 'betterrecs', purpose: 'ajax_cart' %}
{% raw %}
</div>
<div class="ajaxifyDrawer-caret"><span></span></div>
{% endraw %}
</script>
Note the negative margin and large padding. These are to make space in the ajax cart for the recommendations.