I have a use case in which I am replacing post_content in wp_insert_post_data (i.e. replacing swear words), which I prefer to do in PHP.

While saving works, in gutenberg replacements are only visible after page reload.

Also tried hooking into filter rest_pre_insert_{$this->post_type} and data was properly returned in ajax request, but gutenberg editor still didn't update blocks content.

Any ideas how to achieve that?