diff --git a/Makefile b/Makefile
index cda4fe0..5e4df1d 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ csf:
 	vendor/bin/phpcbf --standard=ruleset.xml --extensions=php,phpt --tab-width=4 --ignore=temp -sp src tests
 
 phpstan:
-	vendor/bin/phpstan analyse -l 1 -c phpstan.neon --memory-limit=512M src
+	vendor/bin/phpstan analyse -l 2 -c phpstan.neon --memory-limit=512M src
 
 tests:
 	vendor/bin/tester -s -p php --colors 1 -C tests
diff --git a/phpstan.neon b/phpstan.neon
index 4fc3dfb..67dfdea 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,17 +1,15 @@
 parameters:
 	ignoreErrors:
-		- # object to array
+		- # DataApiObject uses dynamic property access for toArray() serialization
+		  # This is a core PHP pattern for DTOs that serialize via reflection
 			message: '~^Variable property access on \$this\(Tp\\DataApi\\DataApiObject\)\.$~'
 			path: %currentWorkingDirectory%/src/DataApi/DataApiObject.php
-		- # offsetGet, offsetSet
+		- # ArrayAccess implementation requires dynamic method dispatch to getters/setters
 			message: '~^Variable method call on \$this\(Tp\\DataApi\\DataApiObject\)\.$~'
 			path: %currentWorkingDirectory%/src/DataApi/DataApiObject.php
-		- # setProperty, getProperty
+		- # ReturnedPayment hydrates from request args using config-driven property names
 			message: '~^Variable property access on \$this\(Tp\\ReturnedPayment\)\.$~'
 			path: %currentWorkingDirectory%/src/ReturnedPayment.php
-		- # generic formaters
-			message: '~^Variable static method call on Tp\\DataApi\\ValueFormatter\.$~'
-			path: %currentWorkingDirectory%/src/DataApi/ValueFormatter.php
-		- # remote API call
+		- # SoapClient requires dynamic method dispatch for SOAP operations
 			message: '~^Variable method call on SoapClient\.$~'
 			path: %currentWorkingDirectory%/src/Helper/DataApi.php
diff --git a/src/DataApi/DataApiObject.php b/src/DataApi/DataApiObject.php
index 1069746..25b7836 100644
--- a/src/DataApi/DataApiObject.php
+++ b/src/DataApi/DataApiObject.php
@@ -5,6 +5,7 @@
 use ArrayAccess;
 use ReflectionClass;
 use ReflectionMethod;
+use ReflectionNamedType;
 use ReflectionProperty;
 use ReturnTypeWillChange;
 use Tp\Utils;
@@ -49,7 +50,7 @@ static function (ReflectionProperty $property): bool {
 				return self::filterDataProperties($property);
 			}
 		);
-		$sortedDataProperties = static::sortDataProperties($dataProperties);
+		$sortedDataProperties = self::sortDataProperties($dataProperties);
 
 		$propertyNames = [];
 		foreach ($sortedDataProperties as $property) {
@@ -149,7 +150,7 @@ public function offsetSet($offset, $value): void
 			$reflectionMethod = new ReflectionMethod($this, $setterName);
 			$parameterType = $reflectionMethod->getParameters()[0]->getType();
 
-			assert($parameterType !== null);
+			assert($parameterType instanceof ReflectionNamedType);
 
 			switch ($parameterType->getName()) {
 				case 'int':
diff --git a/src/DataApi/Processors/Processor.php b/src/DataApi/Processors/Processor.php
index 41fb02a..b9d6071 100644
--- a/src/DataApi/Processors/Processor.php
+++ b/src/DataApi/Processors/Processor.php
@@ -7,13 +7,6 @@
 abstract class Processor
 {
 
-	public static function process(array $input): array
-	{
-		$instance = new static(); /* @phpstan-ignore-line */
-		// Start with an empty path [].
-		return $instance->processHash($input, []);
-	}
-
 	/**
 	 * @param string[]|int[] $currentPath
 	 */
diff --git a/src/DataApi/ValueFormatter.php b/src/DataApi/ValueFormatter.php
index 94a3a82..172d6b6 100644
--- a/src/DataApi/ValueFormatter.php
+++ b/src/DataApi/ValueFormatter.php
@@ -18,25 +18,23 @@ class ValueFormatter
 	public static function format(string $type, $value)
 	{
 		if (substr($type, -2) === '[]') {
-			return static::formatList(substr($type, 0, -2), $value);
+			return self::formatList(substr($type, 0, -2), $value);
 		}
 
-		$isNull = $value === null;
-		if ($isNull) {
+		if ($value === null) {
 			return null;
 		}
 
-		$method = 'format' . ucfirst($type);
-		if (method_exists(self::class, $method)) {
-			return static::$method($value);
-		}
-
-		if (class_exists($type) && $value instanceof $type) {
-			return $value;
-		}
-
-		$message = 'Unknown type ' . $type . '.';
-		throw new InvalidArgumentException($message);
+		return match ($type) {
+			'int' => self::formatInt($value),
+			'float' => self::formatFloat($value),
+			'bool' => self::formatBool($value),
+			'string' => self::formatString($value),
+			'dateTime' => self::formatDateTime($value),
+			default => class_exists($type) && $value instanceof $type
+				? $value
+				: throw new InvalidArgumentException('Unknown type ' . $type . '.'),
+		};
 	}
 
 	public static function formatInt(?int $value): ?int
diff --git a/src/Payment.php b/src/Payment.php
index c405ca0..bd89d7d 100644
--- a/src/Payment.php
+++ b/src/Payment.php
@@ -358,7 +358,7 @@ public function getArgs(): array
 				'email'     => $customerData->getEmail(),
 			]);
 
-			if ($customerDataArr) {
+			if ($customerDataArr !== []) {
 				$input['customerData'] = Escaper::jsonEncode($customerDataArr);
 			}
 		}
diff --git a/src/Utils.php b/src/Utils.php
index 14b24c7..6fe6b9f 100644
--- a/src/Utils.php
+++ b/src/Utils.php
@@ -50,7 +50,7 @@ public static function isList(array $array): bool
 	{
 		$count = count($array);
 
-		$range = $count
+		$range = $count > 0
 			? range(0, $count - 1)
 			: [];