Multiple vertical tab rows? Rated 4 out of 5 stars

I would like to use this if it allows more than one vertical row of tabs at a time. I frequently have 60 or more tabs in a group all open at once and would like to be able to see them all without having to scroll up or down a vertical tab row or nesting tabs. Does this add-on include the ability to have more than one vertical tab row if you have more tabs open than will fit in a single vertical row without scrolling or nesting?

This review is for a previous version of the add-on ( 

Sorry I guess it is very difficult to be implemented

In short, vertical mode is just changing the style of tab bar
And since Firefox only has one tab bar
No matter how I change the style, it's still in one row

Also it will be over complicated to handle overflown tabs in vertical mode (already too complicated in multi-row mode)