Much prefer that a lost challenge is a penalty point. You'd see a heckuva lot less bricks.
I don't like awarding choice because in folk most choose down but them that give the top guy more time to stall ride and pick up RT. Not in every case but far too often. A penalty point is a very straightforward way to address the issue.
Nobody gonna challenge late in a tie match, unless they are dang certain, knowing they could give away a point.
Also, reviews have to be timed. 2 minutes and done. It shouldn't take 5+ minutes to disect a 20-30 second sequence.
Like some of the other ideas. I like a pushout in principle, but also like the expanded OOB wrestling we have now. But backing off the mat should be an auto stall call, as should crawling off when in a TD position or being ridden.