It would be great if we could see the transaction boundary on the Editor diagram.
e.g. have a dotted line on transaction boundary

• on the service/reference which is marked as suspendTransaction
• around the component if its implementation is marked as managedTransaction.Local
• on the consumer's reference when consumer provides transaction but the producer's implementation is marked as noManagedTransaction
• on the producer's service when consumer doesn't provides transaction but producer's implementation is marked as managedTransaction.Global