Lumbar Spine motion in the downswing

I was watching a two year old video of TW practicing. He was rehearsing keeping his hips deeper through transition to keep from standing up early in the downswing. I noticed his lumbar spine extended significantly, while maintaining forward bend, creating that look of the Sam Snead squat. In your opinion, would attempting to extend the lower spine in this manner be "safe" for a player trying to eliminate "humping the goat" and still trying to maintain speed?

I think you mean this video I've attached?

Tiger is really good at exaggerating movements. Check out this bunker move he was practicing as well!

As far as your question, I would be really careful exaggerating the lumbar extension as long into the downswing as tiger is demonstrating. In general, I think more golfers early extend from not using their abs and taking their hips into extension. Working on flexing the hips is a bigger component to that movement than an exaggerated lumber extension.

If you want more specific guidance to your version of early extension, feel free to post your swing :)