Document how to safely share MoorIsolates

docs/content/en/docs/Advanced Features/isolates.md

@@ -123,8 +123,7 @@ It will disconnect all databases and then close the background isolate, releasin
 
 ## Common operation modes
 
-The `MoorIsolate` object itself can be sent across isolates, so if you have more than one isolate
-from which you want to use moor, that's no problem!
+You can use a `MoorIsolate` across multiple isolates you control and connect from any of them.
 
 __One executor isolate, one foreground isolate__: This is the most common usage mode. You would call
 `MoorIsolate.spawn` from the `main` method in your Flutter or Dart app. Similar to the example above,
@@ -144,6 +143,25 @@ above. The background isolate would _also_ call `MoorIsolate.connect` and create
 of the generated database class. Writes to one database will be visible to the other isolate and
 also update query streams.
 
+To safely send a `MoorIsolate` instance across a `SendPort`, it's recommended to instead send the
+underlying `SendPort` used internally by `MoorIsolate`:
+
+```dart
+// Don't do this, it doesn't work in all circumstances
+void shareMoorIsolate(MoorIsolate isolate, SendPort sendPort) {
+  sendPort.send(isolate);
+}
+
+// Instead, send the underlying SendPort:
+void shareMoorIsolate(MoorIsolate isolate, SendPort sendPort) {
+  sendPort.send(isolate.connectPort);
+}
+```
+
+The receiving end can reconstruct a `MoorIsolate` from a `SendPort` by using the
+`MoorIsolate.fromConnectPort` constructor. That `MoorIsolate` behaves exactly like the original
+one, but we only had to send a primitive `SendPort` and not a complex Dart object.
+
 ## How does this work? Are there any limitations?
 
 All moor features are supported on background isolates and work out of the box. This includes