IN COMMON Theme

Customization Theme
2

I managed to replace accents in category names, but not in cooked posts yet:

<script type="text/discourse-plugin" version="0.1">
 // Remove accents in titles since the font does not support them.
 let stripAccentsFromTitles = function() {
   $('h1, h2, h3, h4, h3 .category-name').each(function(_, e) {
     e.textContent = e.textContent.normalize('NFD').replace(/[\u0300-\u036f]/g, "")
   })
 };

 api.decorateCooked(stripAccentsFromTitles)
</script>