So basically how it works is the shield that you vault off of has to be elevated enough to put you into a falling animation, this then gives you the ability to get a onvault onto the second osa shield but most of the time it will put you ontop of the osa shield making you break it. Just make the second shield far enough until your only vaulting onto the halfdrop instead of on the shield. Only downside to this is its as useful as the psv so only a few spots will probably be found just like the psv. I may be wrong though.
