{% IF goods_modifications.REST_VALUE > 0 %} <link itemprop="availability" href="https://schema.org/InStock" /> <meta itemprop="availability" content="{% IF goods_modifications.REST_VALUE>0 %}in_stock{% ELSE %}out_of_stock{% ENDIF %}" /> {% ENDIF %}
замените на:
<meta itemprop="priceValidUntil" content="2029-12-31"> <!-- информация для поисковика о наличии товара --> <meta itemprop="availability" content="{% IF GOODS_MOD_REST_VALUE>0 %}http://schema.org/InStock{%ELSE %}http://schema.org/OutOfStock{% ENDIF %}">