diff --git a/includes/zones/class-tmdo-zone-router.php b/includes/zones/class-tmdo-zone-router.php
index f941c60..8136cb2 100644
--- a/includes/zones/class-tmdo-zone-router.php
+++ b/includes/zones/class-tmdo-zone-router.php
@@ -104,7 +104,10 @@ class TMDO_Zone_Router {
 	 *
 	 * Callers only need post_id and post_type; zone enumeration and per-zone
 	 * error isolation are handled here. Hot and Cold are skipped when the
-	 * post_type has no registered fields in that zone (table may not exist).
+	 * post_type has no registered fields in that zone, or when the zone table
+	 * was never created (fields are registered long before a module runs).
+	 * Module state is not checked: a table left by a rolled-back module still
+	 * gets its rows for deleted posts removed.
 	 *
 	 * @param int    $post_id   Post ID being deleted.
 	 * @param string $post_type Post type slug.
@@ -113,7 +116,7 @@ class TMDO_Zone_Router {
 	public static function delete_post( int $post_id, string $post_type ): void {
 		$registry = TMDO_Schema_Registry::instance();
 
-		if ( ! empty( $registry->get_hot_columns( $post_type ) ) ) {
+		if ( ! empty( $registry->get_hot_columns( $post_type ) ) && TMDO_Schema_Manager::table_exists( TMDO_Zone_Hot::table( $post_type ) ) ) {
 			try {
 				TMDO_Zone_Hot::delete( $post_id, $post_type );
 			} catch ( \Throwable $e ) {
@@ -121,7 +124,7 @@ class TMDO_Zone_Router {
 			}
 		}
 
-		if ( ! empty( $registry->get_cold_meta_keys( $post_type ) ) ) {
+		if ( ! empty( $registry->get_cold_meta_keys( $post_type ) ) && TMDO_Schema_Manager::table_exists( TMDO_Zone_Cold::table( $post_type ) ) ) {
 			try {
 				TMDO_Zone_Cold::delete( $post_id, $post_type );
 			} catch ( \Throwable $e ) {
diff --git a/tests/live/README.md b/tests/live/README.md
index 6963076..a98aa7c 100644
--- a/tests/live/README.md
+++ b/tests/live/README.md
@@ -38,6 +38,7 @@ Exit code 0 when every test passed, 1 otherwise. Output per test:
 |---|---|
 | `shadow_write` | writes in shadow_read reach native meta (user, term, HivePress listing) |
 | `serialized` | array meta values are stored serialized in flat tables, never "Array" |
+| `zero_side_effect` | zone tables that were never created are never queried on save / delete |
 
 ## Tools (`tools/`)
 
diff --git a/tests/live/suites/zero_side_effect.php b/tests/live/suites/zero_side_effect.php
new file mode 100644
index 0000000..dbbca04
--- /dev/null
+++ b/tests/live/suites/zero_side_effect.php
@@ -0,0 +1,46 @@
+<?php
+/**
+ * Suite: zone tables that were never created are never queried.
+ *
+ * Bug (dev36, 2026-09-26): the HivePress AddOn registers cold fields, so every
+ * save_post / loop_start (PR-054) and every post delete (PR-054b) queried
+ * wp_wpdo_cold_{post_type} although the cold module was idle and the table
+ * did not exist ("table doesn't exist" DB errors on each write).
+ *
+ * @package WP_Data_Optimizer
+ */
+
+declare(strict_types=1);
+
+TMDO_Live::test(
+	'saving and deleting an hp_listing does not touch missing zone tables',
+	static function () {
+		global $wpdb;
+		$tables = array( TMDO_Zone_Cold::table( 'hp_listing' ), TMDO_Zone_Hot::table( 'hp_listing' ) );
+		foreach ( $tables as $table ) {
+			if ( TMDO_Schema_Manager::table_exists( $table ) ) {
+				throw new TMDO_Live_Skip( "{$table} exists on this site" );
+			}
+		}
+
+		$touched = array();
+		$spy     = static function ( $sql ) use ( $tables, &$touched ) {
+			foreach ( $tables as $table ) {
+				if ( false !== strpos( $sql, $table ) && 0 !== stripos( ltrim( $sql ), 'SHOW TABLES' ) ) {
+					$touched[] = $sql;
+				}
+			}
+			return $sql;
+		};
+		add_filter( 'query', $spy );
+		try {
+			$id = TMDO_Live_Fixtures::post( 'hp_listing' );
+			wp_update_post( array( 'ID' => $id, 'post_title' => 'tmdo-live-updated' ) );
+			wp_delete_post( $id, true );
+		} finally {
+			remove_filter( 'query', $spy );
+		}
+
+		tmdo_live_assert_same( array(), $touched, 'queries on missing zone tables' );
+	}
+);
diff --git a/tests/unit/ZoneRouterTest.php b/tests/unit/ZoneRouterTest.php
index 5d8e9e8..80167f1 100644
--- a/tests/unit/ZoneRouterTest.php
+++ b/tests/unit/ZoneRouterTest.php
@@ -21,9 +21,69 @@ class ZoneRouterTest extends TestCase {
 		self::$last_query   = '';
 		self::$last_delete  = [];
 		self::$get_var_return = null;
+		WPDO_Schema_Manager::flush_table_exists_cache();
 		$this->setup_wpdb_mock();
 	}
 
+	/**
+	 * $wpdb mock recording delete() tables; SHOW TABLES reports $existing.
+	 *
+	 * @param string[] $existing Tables that exist.
+	 */
+	private function delete_logger( array &$captured, array $existing ): void {
+		global $wpdb;
+		$wpdb = new class( $captured, $existing ) {
+			public string $prefix = 'wp_';
+			public array  $log;
+			public function __construct( array &$ref, private array $existing ) { $this->log = &$ref; }
+			public function prepare( string $s, mixed ...$a ): string { return str_replace( '%s', (string) ( $a[0] ?? '' ), $s ); }
+			public function query( string $s ): int { return 1; }
+			public function get_var( string $s ): mixed {
+				foreach ( $this->existing as $t ) {
+					if ( "SHOW TABLES LIKE {$t}" === $s ) {
+						return $t;
+					}
+				}
+				return null;
+			}
+			public function insert( string $t, array $d, mixed $f = null ): int { return 1; }
+			public function delete( string $table, array $where, array $formats ): void {
+				$this->log[] = $table;
+			}
+		};
+	}
+
+	private function register_hot_and_cold(): void {
+		$sr = new ReflectionClass( WPDO_Schema_Registry::class );
+		$sr->getProperty( 'instance' )->setValue( null, null );
+		WPDO_Schema_Registry::instance()->register( 'test', array( 'post_type' => 'hp_listing', 'meta_key' => 'hp_price', 'zone' => 'hot', 'column' => 'hp_price', 'type' => 'decimal' ) );
+		WPDO_Schema_Registry::instance()->register( 'test', array( 'post_type' => 'hp_listing', 'meta_key' => 'hp_images', 'zone' => 'cold' ) );
+	}
+
+	/** Registered fields do not mean the zone tables exist (zero side effect). */
+	public function test_delete_post_skips_hot_and_cold_tables_that_do_not_exist(): void {
+		$this->register_hot_and_cold();
+		$captured = array();
+		$this->delete_logger( $captured, array() );
+
+		WPDO_Zone_Router::delete_post( 3, 'hp_listing' );
+
+		$this->assertNotContains( 'wp_wpdo_hot_hp_listing', $captured );
+		$this->assertNotContains( 'wp_wpdo_cold_hp_listing', $captured );
+		$this->assertContains( 'wp_wpdo_warm', $captured );
+	}
+
+	public function test_delete_post_deletes_cold_rows_when_the_table_exists(): void {
+		$this->register_hot_and_cold();
+		$captured = array();
+		$this->delete_logger( $captured, array( 'wp_wpdo_cold_hp_listing' ) );
+
+		WPDO_Zone_Router::delete_post( 4, 'hp_listing' );
+
+		$this->assertContains( 'wp_wpdo_cold_hp_listing', $captured );
+		$this->assertNotContains( 'wp_wpdo_hot_hp_listing', $captured );
+	}
+
 	private function setup_wpdb_mock(): void {
 		global $wpdb;
 		$wpdb = new class {
@@ -204,19 +264,7 @@ class ZoneRouterTest extends TestCase {
 		) );
 
 		$captured = array();
-		global $wpdb;
-		$wpdb = new class( $captured ) {
-			public string $prefix = 'wp_';
-			public array  $log;
-			public function __construct( array &$ref ) { $this->log = &$ref; }
-			public function prepare( string $s, mixed ...$a ): string { return $s; }
-			public function query( string $s ): int { return 1; }
-			public function get_var( string $s ): mixed { return null; }
-			public function insert( string $t, array $d, mixed $f = null ): int { return 1; }
-			public function delete( string $table, array $where, array $formats ): void {
-				$this->log[] = $table;
-			}
-		};
+		$this->delete_logger( $captured, array( 'wp_wpdo_hot_hp_listing' ) );
 
 		WPDO_Zone_Router::delete_post( 10, 'hp_listing' );