Do not use it in case you would want to process parameter sets entering at a high rate. For normal QActions it’s a blocking call and you can get the parameter value of the parameter that triggered it. Queued QActions do not have this blocking call functionality so even if you immediately perform a protocol.GetParameter call you could already retrieve the next parameter value that was present on the setparameter queue. In other words if there are two parameter sets “1” and value “2” on the parameter that triggers the QAction then the QAction will trigger two times but it could be that you read out twice parameter value “2”. Using the inputParameters attribute is also not an alternative to avoid this behavior. I tested this in the past and on a high rate you could also be missing parameter values. As a basic guide I would say only let it trigger by a button parameter that can only have one possible value else you could be doing twice the same thing instead of two different intended actions.