The log lines in question are:
andMSI (s) (10:7C) [15:01:05:803]: PROPERTY CHANGE: Adding MyCustomAction property. Its value is 'Key1=Value1 Key2="Value2" Key3="MyHiddenPropertyValue"'.
What exactly is the point of the Hidden flag if the logging exposes the data anyway?MSI (s) (10:7C) [15:01:19:663]: Executing op: CustomActionSchedule(Action=MyCustomAction,ActionType=3073,Source=BinaryData,Target=MyCustomAction,CustomActionData=Key1=Value1 Key2="Value2" Key3="MyHiddenPropertyValue")