By default, the session established by Flow is not "protected" in any way. This package restricts every request to load the session only, if there are no other requests having it in access currently. It allows to set custom pointcut which will set the session in "ReadOnly" mode, which allows concurrent requests to read, but disallows the current request to write the session.
If you want to allow concurrent access somewhere, you can add your trigger pointcut in Settings.yaml like such:
DigiComp:
FlowSessionLock:
readOnlyExpressions:
MyLock: "method(My\\Package\\Controller\\MyController->myAction())"