Do not need to worry about those elements after all

src/wp-includes/html-api/class-wp-html-open-elements.php

@@ -173,28 +173,6 @@ public function count(): int {
 		return count( $this->stack );
 	}
 
-	/**
-	 * Returns how many nodes are currently in the stack of open elements.
-	 *
-	 * @since 6.7.0
-	 *
-	 * @todo I don't really like this, the proper solution is to not let non-element
-	 *       nodes onto the stack, but this is a way of checking if that approach fixes things.
-	 *
-	 * @return int How many node are in the stack of open elements.
-	 */
-	public function count_elements(): int {
-		$count = 0;
-		for ( $i = count( $this->stack ) - 1; $i >= 0; $i-- ) {
-			$node = $this->stack[ $i ];
-			if ( ctype_upper( $node->node_name[0] ) ) {
-				++$count;
-			}
-		}
-
-		return $count;
-	}
-
 	/**
 	 * Returns the node at the end of the stack of open elements,
 	 * if one exists. If the stack is empty, returns null.
@@ -209,28 +187,6 @@ public function current_node(): ?WP_HTML_Token {
 		return $current_node ? $current_node : null;
 	}
 
-	/**
-	 * Returns the node at the end of the stack of open elements,
-	 * if one exists. If the stack is empty, returns null.
-	 *
-	 * @since 6.7.0
-	 *
-	 * @todo I don't really like this, the proper solution is to not let non-element
-	 *       nodes onto the stack, but this is a way of checking if that approach fixes things.
-	 *
-	 * @return WP_HTML_Token|null Last node in the stack of open elements, if one exists, otherwise null.
-	 */
-	public function current_element_node(): ?WP_HTML_Token {
-		for ( $i = count( $this->stack ) - 1; $i >= 0; $i-- ) {
-			$node = $this->stack[ $i ];
-			if ( ctype_upper( $node->node_name[0] ) ) {
-				return $node;
-			}
-		}
-
-		return null;
-	}
-
 	/**
 	 * Indicates if the current node is of a given type or name.
 	 *

src/wp-includes/html-api/class-wp-html-processor.php

@@ -5068,11 +5068,11 @@ private function generate_implied_end_tags_thoroughly(): void {
 	 * @return WP_HTML_Token|null The adjusted current node.
 	 */
 	private function get_adjusted_current_node(): ?WP_HTML_Token {
-		if ( isset( $this->context_node ) && 1 === $this->state->stack_of_open_elements->count_elements() ) {
+		if ( isset( $this->context_node ) && 1 === $this->state->stack_of_open_elements->count() ) {
 			return $this->context_node;
 		}
 
-		return $this->state->stack_of_open_elements->current_element_node();
+		return $this->state->stack_of_open_elements->current_node();
 	}
 
 	/**