Mega Menu Questions

Hello,
I have two questions about mega menu:

IMAGE #1:
Is there any way to add a second menu row to the menu when using mega menu? i am concerned about what will happen when i have to add more menu options that they just wont fit and will not be bumped to second row of menu.

IMAGE #2:
I noticed that when i scale the screen from my desktop to consider folks with smaller monitors, the menu options on the right get cut off. The mobile menu does end up appearing after i reduce the size of the screen tremendously. I am curious why the menu wont resize dynamically and what to do to correct it.