I do love my Ultralite although I'm afraid I can't remember what my measurements are. One thing I like the most about them is that they're so well-balanced I actually don't have to hold it up at the top of the stock unless I want to. It's important to have a long enough lash to flick nicely but at the same time getting one that's
too long results in it getting stuck in all those moving harness parts at the wrong moment. Eeek!
Been there, done that.
I measured mine to be just in front of the saddle originally and that was a mistake as while I can signal his barrel for bending I can't flick his back when he's lagging, only his neck or withers.

OH! No you aren't supposed to hit their rumps as it does cause bucking but he sure finds it easy to tune out flicking on his withers! I've wished more than once I could flick him on the hindquarters and a whip that went only to the saddle as they recommend would allow me to do that.
You'll like yours. They're so much more comfortable for people with small hands!
Leia