This, of course, doesn't have anything to do with GSX and, in fact, it's a big IMPROVEMENT over the last version and, in fact, it was added by LM following our suggestion to fix this longstanding issue with P3D menus which, I must remind you, are created by the simulator itself and the look and feel is handled entirely by the sim, and it's the same with ALL 3rd party apps using menus.
Why I'm saying this is a vast improvement ?
The most important thing to understand, is the overall menu size window (again, this is the same for ALL 3rd party apps with a menu), depends on the size of the *main* simulator window.
With the previous versions, if the size the sim decided on was too small to include all the menu items, you wouldn't even KNOW you were missing some entries, unless you manually resized the window.
This lead to so many post on this forum about GSX menu entries supposedly "missing", as if it had something to do with GSX...it didn't, of course, it was just the sim that displayed a window too small to show all the entries, and many users don't realize the window CAN be resized.
Following our suggestions that the menu window should always display all the entries it contains, LM changed the menu behavior in version 3.4 so now, instead of menu items being just cut out, if the menu window (at the size the sim has calculated for the current screen size) is not big enough to show all required items, the SIM will add a "Next..." entry automatically, so you will KNOWN there are other items in the menu that didn't fit in the current size.
Of course, the Window CAN still be resized so, as soon the size is enough to show all the entries, the "Next..." option will disappear, and the menu will show all the 10 items it's supposed to show, at most.
This is of course a big improvement over the previous version, and we hoped this would finally stop the constant flow of questions about "missing GSX menu items", because nobody should assume entries are "missing" now.
If, instead of "missing", you now find the menu difficult to use, just resize the menu window, as you were always supposed to do.
The issue about too much space between the lines, is also something totally outside our control, and again, it will look EXACTLY the same with any other 3rd party app with a menu, like SODE, FS Passengers, VRS TacPack, etc.