No, we do not want to tell our site creators to use custom code. We would like a prop or method to determine the heading level for the list of articles in the Latest Posts block. The links are visually headings/titles for articles in a list, and should reflect their heading semantically.
Visual headings that are not semantic headings violate WCAG 1.3.1, Info and Relationships and impedes our ability to meet accessibility standards across all websites.
Asking content creators to implement custom code creates risk of error. There are checkboxes and fields to provide alt text for images, this could be a similar setup to set h tag to ensure these headings follow the structure of the content on the page.