diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index dd9dbc9dc1..80a4de9230 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -120,8 +120,6 @@ jobs:
           git -C ../${{ env.FLOW_FOLDER }} checkout -b build
           composer config repositories.flow '{ "type": "path", "url": "../${{ env.FLOW_FOLDER }}", "options": { "symlink": false } }'
           composer require --no-update neos/flow-development-collection:"dev-build as ${{ env.FLOW_BRANCH_ALIAS }}"
-          # todo remove temporary hack ;) (sorry - if i forget)
-          composer require --no-update --dev "phpstan/phpstan:^1.10.0"
 
       - name: Cache Composer packages
         id: composer-cache
diff --git a/Neos.Eel/Classes/CompilingEvaluator.php b/Neos.Eel/Classes/CompilingEvaluator.php
index 06cf4c18a9..f2d8200285 100644
--- a/Neos.Eel/Classes/CompilingEvaluator.php
+++ b/Neos.Eel/Classes/CompilingEvaluator.php
@@ -97,15 +97,15 @@ protected function evaluateAndUnwrap(\closure $expressionFunction, Context $cont
      */
     protected function generateEvaluatorCode($expression)
     {
-        /** @phpstan-ignore-next-line */
+        /** @phpstan-ignore-next-line `CompilingEelParser` has been explicitly excluded from analysis, because it contains generated code that is impossible to fix */
         $parser = new CompilingEelParser($expression);
         $result = $parser->match_Expression();
 
         if ($result === false) {
             throw new ParserException(sprintf('Expression "%s" could not be parsed.', $expression), 1344513194);
-            /** @phpstan-ignore-next-line */
+            /** @phpstan-ignore-next-line $parser->pos appears to be undeclared, because instantiation of $parser is hidden as well */
         } elseif ($parser->pos !== strlen($expression)) {
-            /** @phpstan-ignore-next-line */
+            /** @phpstan-ignore-next-line $parser->pos appears to be undeclared, because instantiation of $parser is hidden as well */
             throw new ParserException(sprintf('Expression "%s" could not be parsed. Error starting at character %d: "%s".', $expression, $parser->pos, substr($expression, $parser->pos)), 1327682383);
         } elseif (!array_key_exists('code', $result)) {
             throw new ParserException(sprintf('Parser error, no code in result %s ', json_encode($result)), 1334491498);
diff --git a/Neos.Eel/Classes/InterpretedEvaluator.php b/Neos.Eel/Classes/InterpretedEvaluator.php
index 1f653e6ebc..b113e065b1 100644
--- a/Neos.Eel/Classes/InterpretedEvaluator.php
+++ b/Neos.Eel/Classes/InterpretedEvaluator.php
@@ -35,9 +35,12 @@ public function evaluate($expression, Context $context)
 
         if ($res === false) {
             throw new ParserException(sprintf('Expression "%s" could not be parsed.', $expression), 1344514198);
-            /** @phpstan-ignore-next-line */
+            /**
+             * @phpstan-ignore-next-line $parser->pos appears to be undeclared, because it is declared up in the parent class chain of `InterpretedEelParser`,
+             * wherein multiple classes (e.g. `EelParser` and `AbstractEelParser`) are explicitly excluded from analysis, because they contain generated code that is impossible to fix
+             */
         } elseif ($parser->pos !== strlen($expression)) {
-            /** @phpstan-ignore-next-line */
+            /** @phpstan-ignore-next-line $parser->pos appears to be undeclared see comment above. */
             throw new ParserException(sprintf('Expression "%s" could not be parsed. Error starting at character %d: "%s".', $expression, $parser->pos, substr($expression, $parser->pos)), 1344514188);
         } elseif (!array_key_exists('val', $res)) {
             throw new ParserException(sprintf('Parser error, no val in result %s ', json_encode($res)), 1344514204);
diff --git a/Neos.Flow/Classes/Aop/Advice/AdviceChain.php b/Neos.Flow/Classes/Aop/Advice/AdviceChain.php
index 2312a8106d..21da910d4b 100644
--- a/Neos.Flow/Classes/Aop/Advice/AdviceChain.php
+++ b/Neos.Flow/Classes/Aop/Advice/AdviceChain.php
@@ -11,7 +11,7 @@
  * source code.
  */
 use Neos\Flow\Aop\JoinPointInterface;
-use Neos\Flow\Aop\ProxyInterface;
+use Neos\Flow\Aop\ProxyInterface as InternalAopProxyInterface;
 
 /**
  * The advice chain holds a number of subsequent advices that
@@ -57,7 +57,7 @@ public function proceed(JoinPointInterface &$joinPoint)
         if ($this->adviceIndex < count($this->advices)) {
             $result = $this->advices[$this->adviceIndex]->invoke($joinPoint);
         } else {
-            /** @var ProxyInterface $proxy */
+            /** @var InternalAopProxyInterface $proxy */
             $proxy = $joinPoint->getProxy();
             $result = $proxy->Flow_Aop_Proxy_invokeJoinpoint($joinPoint);
         }
diff --git a/Neos.Flow/Classes/Cli/Response.php b/Neos.Flow/Classes/Cli/Response.php
index 5e44675549..0fedb619d0 100644
--- a/Neos.Flow/Classes/Cli/Response.php
+++ b/Neos.Flow/Classes/Cli/Response.php
@@ -47,7 +47,7 @@ class Response
     private $content = '';
 
     /**
-     * @var boolean|int
+     * @var bool|int
      */
     private $colorSupport;
 
@@ -118,7 +118,6 @@ public function getContent(): string
     /**
      * Sets color support / styled output to yes, no or auto detection
      *
-     * @deprecated and will be removed https://github.com/neos/flow-development-collection/pull/3262
      * @param boolean $colorSupport true, false or NULL (= autodetection)
      * @return void
      */
diff --git a/Neos.Flow/Classes/Command/ResourceCommandController.php b/Neos.Flow/Classes/Command/ResourceCommandController.php
index 156cf3e227..dcb2ec7b95 100644
--- a/Neos.Flow/Classes/Command/ResourceCommandController.php
+++ b/Neos.Flow/Classes/Command/ResourceCommandController.php
@@ -24,7 +24,6 @@
 use Neos\Flow\ResourceManagement\ResourceManager;
 use Neos\Flow\ResourceManagement\ResourceRepository;
 use Neos\Media\Domain\Repository\AssetRepository;
-
 use Neos\Media\Domain\Repository\ThumbnailRepository;
 
 /**
@@ -239,7 +238,7 @@ public function cleanCommand()
             foreach ($brokenResources as $key => $resourceIdentifier) {
                 $resource = $this->resourceRepository->findByIdentifier($resourceIdentifier);
                 $brokenResources[$key] = $resource;
-                if ($mediaPackagePresent && class_exists(AssetRepository::class) && class_exists(ThumbnailRepository::class)) {
+                if ($mediaPackagePresent && $assetRepository !== null && $thumbnailRepository !== null) {
                     $assets = $assetRepository->findByResource($resource);
                     if ($assets !== null) {
                         $relatedAssets[$resource] = $assets;
@@ -281,7 +280,7 @@ public function cleanCommand()
                         ]);
                         $resource->disableLifecycleEvents();
                         $this->resourceRepository->remove($resource);
-                        if ($mediaPackagePresent && class_exists(AssetRepository::class) && class_exists(ThumbnailRepository::class)) {
+                        if ($mediaPackagePresent && $assetRepository !== null && $thumbnailRepository !== null) {
                             if (isset($relatedAssets[$resource])) {
                                 foreach ($relatedAssets[$resource] as $asset) {
                                     $assetRepository->removeWithoutUsageChecks($asset);
diff --git a/Neos.Flow/Classes/Log/ThrowableStorage/FileStorage.php b/Neos.Flow/Classes/Log/ThrowableStorage/FileStorage.php
index 347978897b..c20b65b99c 100644
--- a/Neos.Flow/Classes/Log/ThrowableStorage/FileStorage.php
+++ b/Neos.Flow/Classes/Log/ThrowableStorage/FileStorage.php
@@ -267,7 +267,6 @@ protected function cleanupThrowableDumps(): void
             $cutoffTime = time() - $this->maximumThrowableDumpAge;
 
             $iterator = new \DirectoryIterator($this->storagePath);
-            /** @var \DirectoryIterator $directoryEntry */
             foreach ($iterator as $directoryEntry) {
                 if ($directoryEntry->isFile() && $directoryEntry->getCTime() < $cutoffTime) {
                     unlink($directoryEntry->getRealPath());
diff --git a/Neos.FluidAdaptor/Classes/Core/Cache/CacheAdaptor.php b/Neos.FluidAdaptor/Classes/Core/Cache/CacheAdaptor.php
index f7272f0da3..43bb16e5a4 100644
--- a/Neos.FluidAdaptor/Classes/Core/Cache/CacheAdaptor.php
+++ b/Neos.FluidAdaptor/Classes/Core/Cache/CacheAdaptor.php
@@ -61,7 +61,7 @@ public function set($name, $value)
      * the entire cache if no entry is provided.
      *
      * @param string|null $name
-     * @return bool|void
+     * @return bool|null
      */
     public function flush($name = null)
     {
@@ -69,6 +69,7 @@ public function flush($name = null)
             return $this->flowCache->remove($name);
         } else {
             $this->flowCache->flush();
+            return null;
         }
     }
 
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 1c75e8a6cb..2d8a0153ee 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -26,6 +26,7 @@ parameters:
     excludePaths:
         analyse:
             - Neos.Flow/.phpstorm.meta.php
+            # The parsers are autogenerated / extending autogenerated code and not analysable
             - Neos.Eel/Classes/FlowQuery/FizzleParser.php
             - Neos.Eel/Classes/AbstractParser.php
             - Neos.Eel/Classes/EelParser.php