Canvas opacity instead of css

src/ol/renderer/canvas/VectorLayer.js

@@ -67,6 +67,16 @@ class CanvasVectorLayerRenderer extends CanvasLayerRenderer {
     this.replayGroupChanged = true;
   }
 
+  /**
+   * @inheritDoc
+   */
+  useContainer(target, transform) {
+    if (this.getLayer().getOpacity() < 1) {
+      target = null;
+    }
+    super.useContainer(target, transform);
+  }
+
   /**
    * @inheritDoc
    */