From my experience you should generally not make any assumptions on "if", "when" or "how often" a datasource microflow is called after triggering an action.
If you have a more complex visibility or refresh other objects on your page, your datasource microflow may even run more than once.
Usually a datasource microflow should create the same result when run with the same parameters. If it properly works like that you should have no side effects. So what kind of problems do you have with that?