Either way should have the same effect, but you only really need to worry if it reverses while in forward motion with tension on the lines. If you
try and hold it steady in light winds, it will often start to reverse - that's just the design/AOA of the kite and why it can reverse launch in two
line mode. It's not a problem when you're in motion unless you turn too much towards the kite and stall it but even then, a quick backwards loop
sorts it pretty quick.
If it continues to be a problem, and you still have a little slack on the brake lines, then make the diagonal part of the Z bridle a tad longer (a tad
is roughly equivalent to 3.75mm) (humor)! Too much and you get back into 'flappy' mode.
It's sort of the opposite problem to high aspect kites - try and hold them at the edge of the window without a little brake and they'll just overfly.
The Nasa's will sit overhead very nicely if you've got some breeze but if you get a lull then yeah, they can go into reverse.