diff --git a/changelog.txt b/changelog.txt
index f537fca201..126f7233c3 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -30,6 +30,8 @@
 * Update - Add nightly task and WooCommerce tool to remove stale entries from our database cache
 * Dev - Make 'Add to cart' more robust in e2e tests
 * Dev - Ensure e2e tests enable or disable Optimized Checkout during setup
+* Tweak - Improve how we cache saved payment methods for customers
+* Dev - Fix some e2e issues: timing, optional flows, and WooCommerce RC support
 
 = 9.8.1 - 2025-08-15 =
 * Fix - Remove connection type requirement from PMC sync migration attempt
diff --git a/includes/class-wc-stripe-api.php b/includes/class-wc-stripe-api.php
index 4aaa84d30e..f5f62e95b1 100644
--- a/includes/class-wc-stripe-api.php
+++ b/includes/class-wc-stripe-api.php
@@ -504,16 +504,22 @@ public static function update_payment_method( $payment_method_id, $payment_metho
 	public static function attach_payment_method_to_customer( string $customer_id, string $payment_method_id ) {
 		// Sources and Payment Methods need different API calls.
 		if ( 0 === strpos( $payment_method_id, 'src_' ) ) {
-			return self::request(
+			$result = self::request(
 				[ 'source' => $payment_method_id ],
 				'customers/' . $customer_id . '/sources'
 			);
+		} else {
+			$result = self::request(
+				[ 'customer' => $customer_id ],
+				'payment_methods/' . $payment_method_id . '/attach'
+			);
 		}
 
-		return self::request(
-			[ 'customer' => $customer_id ],
-			'payment_methods/' . $payment_method_id . '/attach'
-		);
+		if ( empty( $result->error ) ) {
+			WC_Stripe_Customer::clear_customer_cache( $customer_id, $payment_method_id );
+		}
+
+		return $result;
 	}
 
 	/**
@@ -534,17 +540,24 @@ public static function detach_payment_method_from_customer( string $customer_id,
 
 		// Sources and Payment Methods need different API calls.
 		if ( 0 === strpos( $payment_method_id, 'src_' ) ) {
-			return self::request(
+			$result = self::request(
 				[],
 				'customers/' . $customer_id . '/sources/' . $payment_method_id,
 				'DELETE'
 			);
+		} else {
+			$result = self::request(
+				[],
+				'payment_methods/' . $payment_method_id . '/detach'
+			);
 		}
 
-		return self::request(
-			[],
-			'payment_methods/' . $payment_method_id . '/detach'
-		);
+		if ( empty( $result->error ) ) {
+			// Clear cached payment methods.
+			WC_Stripe_Customer::clear_customer_cache( $customer_id, $payment_method_id );
+		}
+
+		return $result;
 	}
 
 	/**
diff --git a/includes/class-wc-stripe-customer.php b/includes/class-wc-stripe-customer.php
index ec5bab0d42..04d5071608 100644
--- a/includes/class-wc-stripe-customer.php
+++ b/includes/class-wc-stripe-customer.php
@@ -33,6 +33,11 @@ class WC_Stripe_Customer {
 	 */
 	const PAYMENT_METHODS_TRANSIENT_KEY = 'stripe_payment_methods_';
 
+	/**
+	 * Cache prefix for all saved payment methods per customer.
+	 */
+	protected const ALL_PAYMENT_METHODS_CACHE_PREFIX = 'all_payment_methods_';
+
 	/**
 	 * Queryable Stripe payment method types.
 	 */
@@ -712,6 +717,7 @@ public function attach_source( $source_id ) {
 		} elseif ( empty( $response->id ) ) {
 			return new WP_Error( 'error', __( 'Unable to add payment source.', 'woocommerce-gateway-stripe' ) );
 		} else {
+			$this->customer_data = [];
 			return $response;
 		}
 	}
@@ -813,8 +819,8 @@ public function get_all_payment_methods( array $payment_method_types = [], int $
 			return [];
 		}
 
-		$cache_key = self::PAYMENT_METHODS_TRANSIENT_KEY . '__all_' . $this->get_id();
-		$all_payment_methods = get_transient( $cache_key );
+		$cache_key           = self::ALL_PAYMENT_METHODS_CACHE_PREFIX . $this->get_id();
+		$all_payment_methods = WC_Stripe_Database_Cache::get( $cache_key );
 
 		if ( false === $all_payment_methods || ! is_array( $all_payment_methods ) ) {
 			$all_payment_methods    = [];
@@ -839,7 +845,7 @@ public function get_all_payment_methods( array $payment_method_types = [], int $
 						&& 'resource_missing' === $response->error->code
 					) {
 						// If the customer doesn't exist, cache an empty array.
-						set_transient( $cache_key, [], DAY_IN_SECONDS );
+						WC_Stripe_Database_Cache::set( $cache_key, [], DAY_IN_SECONDS );
 					}
 					return [];
 				}
@@ -862,7 +868,7 @@ public function get_all_payment_methods( array $payment_method_types = [], int $
 			} while ( null !== $last_payment_method_id );
 
 			// Always cache the result without any filters applied.
-			set_transient( $cache_key, $all_payment_methods, DAY_IN_SECONDS );
+			WC_Stripe_Database_Cache::set( $cache_key, $all_payment_methods, DAY_IN_SECONDS );
 		}
 
 		// If there are no payment methods, no need to apply any filters below.
@@ -901,7 +907,7 @@ public function delete_source( $source_id ) {
 		$response = WC_Stripe_API::detach_payment_method_from_customer( $this->get_id(), $source_id );
 
 		if ( empty( $response->error ) ) {
-			$this->clear_cache( $source_id );
+			$this->customer_data = [];
 			do_action( 'wc_stripe_delete_source', $this->get_id(), $response );
 
 			return true;
@@ -923,7 +929,7 @@ public function detach_payment_method( $payment_method_id ) {
 		$response = WC_Stripe_API::detach_payment_method_from_customer( $this->get_id(), $payment_method_id );
 
 		if ( empty( $response->error ) ) {
-			$this->clear_cache( $payment_method_id );
+			$this->customer_data = [];
 			do_action( 'wc_stripe_detach_payment_method', $this->get_id(), $response );
 
 			return true;
@@ -988,17 +994,37 @@ public function set_default_payment_method( $payment_method_id ) {
 	 * @param string|null $payment_method_id The ID of the payment method to clear cache for, if specified.
 	 */
 	public function clear_cache( $payment_method_id = null ) {
-		delete_transient( 'stripe_sources_' . $this->get_id() );
-		delete_transient( 'stripe_customer_' . $this->get_id() );
+		if ( empty( $this->get_id() ) ) {
+			return;
+		}
+
+		self::clear_customer_cache( $this->get_id(), $payment_method_id );
+		$this->customer_data = [];
+	}
+
+	/**
+	 * Clears cached data, especially payment methods, for a specified customer.
+	 *
+	 * @param string $customer_id            The ID of the customer to clear cache for.
+	 * @param string|null $payment_method_id The optional payment method ID to clear cache for.
+	 */
+	public static function clear_customer_cache( string $customer_id, ?string $payment_method_id = null ): void {
+		if ( empty( $customer_id ) ) {
+			return;
+		}
+
+		delete_transient( 'stripe_sources_' . $customer_id );
+		delete_transient( 'stripe_customer_' . $customer_id );
 		foreach ( self::STRIPE_PAYMENT_METHODS as $payment_method_type ) {
-			delete_transient( self::PAYMENT_METHODS_TRANSIENT_KEY . $payment_method_type . $this->get_id() );
+			delete_transient( self::PAYMENT_METHODS_TRANSIENT_KEY . $payment_method_type . $customer_id );
 		}
-		delete_transient( self::PAYMENT_METHODS_TRANSIENT_KEY . '__all_' . $this->get_id() );
+
+		WC_Stripe_Database_Cache::delete( self::ALL_PAYMENT_METHODS_CACHE_PREFIX . $customer_id );
+
 		// Clear cache for the specific payment method if provided.
 		if ( $payment_method_id ) {
 			WC_Stripe_Database_Cache::delete( 'payment_method_for_source_' . $payment_method_id );
 		}
-		$this->customer_data = [];
 	}
 
 	/**
diff --git a/readme.txt b/readme.txt
index 06bcde1e4c..748ae72a71 100644
--- a/readme.txt
+++ b/readme.txt
@@ -140,5 +140,7 @@ If you get stuck, you can ask for help in the [Plugin Forum](https://wordpress.o
 * Update - Add nightly task and WooCommerce tool to remove stale entries from our database cache
 * Dev - Make 'Add to cart' more robust in e2e tests
 * Dev - Ensure e2e tests enable or disable Optimized Checkout during setup
+* Tweak - Improve how we cache saved payment methods for customers
+* Dev - Fix some e2e issues: timing, optional flows, and WooCommerce RC support
 
 [See changelog for full details across versions](https://raw.githubusercontent.com/woocommerce/woocommerce-gateway-stripe/trunk/changelog.txt).