Don't do it unless you are a trail rider. Far too dangerous going through the trees. I have so many guys telling me about their horror stories and why they now want a Cordless Teth-Air or Phantom Teth-Air. This can only cause a whole bunch of new problems when branches mash the throttle.
I've been riding a finger throttle or a flipped/finger throttle for 8 years. Two sleds previous without handguards. My current one has barkbuster moto guards (as much for actual branch smashing as because of the finger throttle).
I know this will bite me in the a$$ for actually typing this publicly but I have NEVER run the throttle into something that activated it. A lot of that has to do with the fact that like everyone says, it ends up facing more down than forward. But you can also ride with one finger on the paddle and another finger behind the paddle so little pinner branches don't pulse it as you pass. But the idea that this should only be done by trail riders is kind of funny to those of us who have been doing it for a long time.
I don't disagree that some good handguards are a good idea.....doesn't hurt. I just considered that as only par of the reason for them.......along with punching branches and early cold mornings.
I should take pics of all the wood and bark marks on the front of my sled right now...........you know.......for credentials
Tether cords and branches however...... That's affected my riding through branches way more.