I am experimenting with composite jigxs so I can start creating reusable components.
I am trying to save the data on the mainform using action.submit-form, but it is throwing an error stating expression is not valid.
action.submit-form requires a formId as part of the configuration. Looking at the schema formId can only take text and does not allow an expression, that is the reason why you see the validation error. The best would be to make use of action.execute-entity.