diff --git a/.github/workflows/test_basic.yaml b/.github/workflows/test_basic.yaml
index 398cb039..99868f09 100644
--- a/.github/workflows/test_basic.yaml
+++ b/.github/workflows/test_basic.yaml
@@ -11,12 +11,15 @@ jobs:
             github.event.pull_request.user.login == 'dop-amin' ||
             github.event.pull_request.user.login == 'mkannwischer'
             }}
-    runs-on: ubuntu-latest
-    strategy: 
-      matrix:      
+    runs-on: macos-latest
+    strategy:
+      matrix:
         target: [slothy.targets.arm_v7m.cortex_m7,slothy.targets.arm_v81m.cortex_m55r1, slothy.targets.arm_v81m.cortex_m85r1, slothy.targets.aarch64.cortex_a55, slothy.targets.aarch64.cortex_a72_frontend, slothy.targets.aarch64.apple_m1_firestorm_experimental, slothy.targets.aarch64.apple_m1_icestorm_experimental]
     steps:
     - uses: actions/checkout@v3
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
     - name: Install python dependencies
       run: |
         python3 -m venv venv
@@ -31,9 +34,12 @@ jobs:
             github.event.pull_request.user.login == 'dop-amin' ||
             github.event.pull_request.user.login == 'mkannwischer'
             }}
-    runs-on: ubuntu-latest
+    runs-on: macos-latest
     steps:
     - uses: actions/checkout@v3
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
     - name: Install python dependencies
       run: |
         python3 -m venv venv
@@ -48,9 +54,12 @@ jobs:
             github.event.pull_request.user.login == 'dop-amin' ||
             github.event.pull_request.user.login == 'mkannwischer'
             }}
-    runs-on: ubuntu-latest
+    runs-on: macos-latest
     steps:
     - uses: actions/checkout@v3
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
     - name: Install python dependencies
       run: |
         python3 -m venv venv
@@ -65,9 +74,12 @@ jobs:
             github.event.pull_request.user.login == 'dop-amin' ||
             github.event.pull_request.user.login == 'mkannwischer'
             }}
-    runs-on: ubuntu-latest
+    runs-on: macos-latest
     steps:
     - uses: actions/checkout@v3
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
     - name: Install python dependencies
       run: |
         python3 -m venv venv
@@ -75,16 +87,19 @@ jobs:
         echo BASH_ENV="./venv/bin/activate" >> $GITHUB_ENV
     - name: Run examples
       run: |
-        python3 example.py --examples ntt_kyber_1_23_45_67_m55,ntt_dilithium_12_34_56_78_m55 --timeout=300
+        python3 example.py --examples ntt_kyber_1_23_45_67_m55,ntt_dilithium_12_34_56_78_m55 --timeout=1200
   examples_ntt_kyber_dilithium_neon_core:
     if: ${{ github.event.label.name == 'needs-ci' ||
             github.event.pull_request.user.login == 'hanno-becker' ||
             github.event.pull_request.user.login == 'dop-amin' ||
             github.event.pull_request.user.login == 'mkannwischer'
             }}
-    runs-on: ubuntu-latest
+    runs-on: macos-latest
     steps:
     - uses: actions/checkout@v3
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
     - name: Install python dependencies
       run: |
         python3 -m venv venv
@@ -92,16 +107,19 @@ jobs:
         echo BASH_ENV="./venv/bin/activate" >> $GITHUB_ENV
     - name: Run examples
       run: |
-        python3 example.py --examples ntt_kyber_123_4567_a55,ntt_dilithium_123_45678_a55 --timeout=300
+        python3 example.py --examples ntt_kyber_123_4567_a55,ntt_dilithium_123_45678_a55 --timeout=1200
   sqmag:
     if: ${{ github.event.label.name == 'needs-ci' ||
             github.event.pull_request.user.login == 'hanno-becker' ||
             github.event.pull_request.user.login == 'dop-amin' ||
             github.event.pull_request.user.login == 'mkannwischer'
             }}
-    runs-on: ubuntu-latest
+    runs-on: macos-latest
     steps:
     - uses: actions/checkout@v3
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
     - name: Install python dependencies
       run: |
         python3 -m venv venv
@@ -116,9 +134,12 @@ jobs:
             github.event.pull_request.user.login == 'dop-amin' ||
             github.event.pull_request.user.login == 'mkannwischer'
             }}
-    runs-on: ubuntu-latest
+    runs-on: macos-latest
     steps:
     - uses: actions/checkout@v3
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
     - name: Install python dependencies
       run: |
         python3 -m venv venv
diff --git a/requirements.txt b/requirements.txt
index b1f405e9..a6f8c9cd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 numpy==1.26.4
-ortools==9.7.2996
+ortools==9.11.4210
 pandas==2.1.1
 sympy==1.12
diff --git a/slothy/core/core.py b/slothy/core/core.py
index bfbaeab4..8055d221 100644
--- a/slothy/core/core.py
+++ b/slothy/core/core.py
@@ -3322,6 +3322,8 @@ def _init_external_model_and_solver(self):
         self._model.cp_solver = cp_model.CpSolver()
         self._model.cp_solver.random_seed = self.config.solver_random_seed
 
+        self._model.cp_solver.parameters.num_workers = 16
+
     def _NewIntVar(self, minval, maxval, name=""): # pylint:disable=invalid-name
         r = self._model.cp_model.NewIntVar(minval,maxval, name)
         self._model.variables.append(r)
@@ -3413,7 +3415,7 @@ def is_good_enough( cur, bound ):
                    cur <= self.config.objective_lower_bound:
                     self.logger.info("Reached user-defined objective_lower_bound ... stop")
                     return True
-            return False
+            return True
 
         solution_cb = SlothyBase.CpSatSolutionCb(self.logger,self._model.objective_name,
                                                  self.config.max_solutions,