You know, this is the catch 22 with thumb injuries. There are several different types of crashes that can cause different risks to the thumb. I think in a yard sale/tumbling fall something like the S trigger design could be beneficial. My controlled "crash" was me hitting a patch of ice on early season man-made snow and just putting my fist down to brace myself and pop back up (I was on my right hip for all of 1-2 seconds). There was no torqueing out of my thumb at all like many "skier's thumb" injuries to the UCL, it was just the odd shape of grip and hard plastic of the grip digging into my UCL and the pressure of the snow near my thumbnail that kind of forced that joint open. I have no doubt that with a softer material with rounded grips against that joint, or even the old school pistol grips that caused other thumb injuries, it would have been like 100's of times before where I brace myself with my fist and pop right back up without incident.
A ski buddy from the 80's broke his thumb once and afterwards bought these crazy grips that had a hole for your thumb to go into so that it was completely surrounded by plastic and he swore by them even though they looked cumbersome. That style grip would have absolutely protected my thumb from this injury but they must have proven to have other issues (or just looked too weird) to keep making them. I looked for a pair on ebay after my injury to at least protect my thumb while the injury healed but just skied without poles with a roll of tape supporting it.
You'd think with all of the innovation going on, someone could come up with a ski pole, grip or glove design that would better protect our thumbs once and for all. I thought about trying the Level thumb protection gloves but don't see many reviews so I don't know that those are the answer. Maybe adding this thumb guard Leki offers would have protected my thumbs by keeping the thumb off the snow. Do you think in more of a tumbling type fall those could either catch my thumb or the snow and cause a different type of thumb injury? They cost almost as much as another set of poles so I may just cut the poles down, put on normal grips and give them to my kids and continue on with traditional ski poles.