Yes, I need to use it because I'm migrating an existing application and I need to keep compatibility with existing code. As I explain above, the menu in my application is dynamically created and I have lot of existing code to do it based in standard vcl TMainMenu. May be in short I can directly use jqMenu, but now I need to reuse the most possible my existing code.
I think that the right thing should be to assign to userdata the pointer to the original TMenuItem object. I don't know if this could cause any memory problem.
Another option is to add the tag property to TIWCGJQMenuItem. I don't see accurate to assign the tag to UserData, it would be confuse to other users. If this is the only solution I prefer to do it my own in my sourcecode. I already buy it 2 hours ago
The problem is not adding a property, this only takes a few seconds to add, the problem is that we need to consider every property in detail, because it takes memory, and at least for Win32 Web Apps, is something that we always have to consider, specially when we already have a property for that purpose.