SaveTheWhales said..
I did try the 10m on my standard 4 line bar in 35 ish knots and it still flew ok - but the leading edge with less support would flare a bit and could be felt through the bar. Will be ok to use your lower Y bar for a quick demo and tweak it later if need be.
i just use a line stopper and a ring - on the 'NON' flag out front line...

Nathe said..
Have to disagree with the low v. I changed the bar on my xr5 to a low split and it didn't make a difference at all. The throw on the core bars are huge and was real uncomfortable ride.
Give the others bars a shot you might find they work fine