Hi Pankaj,
Thanks for the note back. Though, if the dev team added a function so that when the columns stack that the text shown shows the parent item or group title this will not impact workflow. It will make it easy to see which on is which without having to open each. For menus with many column blocks, there is just no way to tell.
Also, separate from this request, there is still the issue of the bug I have mentioned couple times. To recreate this, make a menu with 5,6,7 columns so they stack like in my screen shots. Then just try moving them around into another position. You will see that the blocks jerk, shake, and sometimes do not want to go into place. It seems to be slightly intermittent but will happen 100% if you attempt to move a few times. It just makes managing the large menu difficult.
Both these notes if corrected will improve the admin UI for a better experience.
Thanks