I randomly thought "wait, if the Id and Super-Ego functions are sort of cycled around within a quadra, doesn't that mean that someone if your quadra will have their Demonstrative on your PoLR? Wait, wouldn't you also have yours on theirs in that case?" Then I realized that that happens in the oft-praised duality. So, not only are you and your dual not much alike, it's probably the only intra-quadra relationship that has the potential to become actively strained. Your options are 1. Keep your demonstrative hidden away all the time or 2. Both of you use it and make things very, very awkward for one another. I think duality is probably still pretty good as far as intertype relations go, but it has that issue, which, say, mirror or activator don't.