[CONNECT C++] mdlDialog_sendMessagesOnUnload()

I have a couple of dialog hook classes that release memory in the _Destroy event.  I noticed that I am seeing  an Internal Access Violation message from MicroStation if I unload the app. when the dialog is open.  The _Destroy event was not being called in my hook classes.  I added this call to MdlMain:

const bool SendUnloadMessages { true };
mdlDialog_sendMessagesOnUnload (mdlSystem_getCurrMdlDesc (), SendUnloadMessages);

That seemed to eliminate the problem. 

1. Is there any downside to using that call? 
2. Why aren't unload messages sent to dialog item hooks by default when an app. is unloaded? 
3. Would there be any unwanted consequence if I were to put that call into all my apps. (even those with no dialog hook classes)?