MDI is an "mIRC issue" because it's an inherent part of mIRC's UI that is not going away any time soon. Khaled has stated on the forums a few times that he is not removing MDI. The most relevant post I could find using the horrible forum search is:

https://forums.mirc.com/ubbthreads.php?ubb=showflat&Number=222677&page=6&PHPSESSID=af

But I'm fairly sure there was a more direct "MDI will not be removed" response.

If your point was to educate me about MDI, thanks, but I already know what it is.