Thanks guys!
Depends on where you compete. My focus is on advanced and development of Leg Locks for MMA and Submission Grappling.
NAGA, Grapples Quest, Abu Dhabi, MMA has no rules against "reaping the knee" from top position.
I'm not sure what the rule is for top position in the IBJJF, I know for sure the Reaper set ups I use from the bottom are illegal. You would have to ask them.
I do know that US Grappling (That runs the Submission Only events) has made anything (from the top or bottom) across the knee illegal except in the advanced division. So everying in the above video except for "The Clamp" position would be illegal.