I think what you have suggested – a separate block with a single trial – is a good way to go. Any other ideas I’m coming up with are far more hacky and difficult to manage. Using a separate block means you can have an easy to manage split in the logic of your stateflow code based on a TP table parameter – instruction trial vs work trial.
Is there a different way you’d like to see something like this work? We are always open to suggestions for new features.