Pull commentdata for pre_comment_on_post from comment_post_ID

You can use the preprocess_comment inside wp_new_comment() filter to access/modify the data of the comment that is going to be written.

“`

/**
 * Filters a comment's data before it is sanitized and inserted into the database.
 *
 * @since 1.5.0
 *
 * @param array $commentdata Comment data.
 */
$commentdata = apply_filters( 'preprocess_comment', $commentdata );

just make sure you hook after the plugin in question (using a greater priority) in order your filter to come afterwards whatever the plugin does to $commentdata or before it (using a lower filter priority) if you need to process $commentdata before it’s passed to the plugin. See add_filter’s docs if $priority argument is new to you.