I see no reason why you can't stay in a snaffle at this point.
Yes, I was going to comment on your turns. Now for the first barrel, the video starts so abruptly that I cannot tell if Poncho was on the correct lead or not for the first barrel. So make sure you lope circles with him beforehand and do not head for that first barrel until he is on the correct lead.
Your first barrel pocket is a tad bit too wide. He "bursts" into the turn (which is why I'm not sure if he was maybe on the wrong lead before that) or if he just "remembered" he was suppose to turn.
What I like to do with my young horses who are just loping the pattern, is after we have completed the first barrel, I break them down into a trot for one stride so that I can pick them up into the correct lead for the second barrel. Poncho did switch at the last second at your second barrel, but I just always figure it is easier for them if you tell them when to switch in the early stages.
Now here's what I see happening in your turns and his "shouldering in" because you can really tell on your third barrel. You are holding him off to keep him from turning by using your outside rein to hold his nose off until you are ready to turn. That's a no-no.
When you pull his nose to the outside, you are losing that perfect bend he should have in his body when he's ready to turn. And when you pull a horse's nose to the outside in a barrel run, that's when they shoulder in and either duck away from the barrel, or else they plain hit the barrel.
Instead what you should be doing to hold him off on the turns until the pocket is right, is you should use your inside leg to push him away from the barrel, but keep contact on your inside rein and keep his nose inward. That way, he still maintains the correct bend in his body, and that shoulder stays elevated (not dropped). So use your inside leg.
Another thing you can do to keep the shoulder elevated is to change your hand position. Right now it looks like you kind of keep your hand close to the saddle horn, but off to the side. Instead:
Let's say we are going to make a left turn. Starting with the palm of your hand facing down (fingers wrapped around the rein), rotate your left wrist counter-clockwise to "lift up" on the rein, and then move your left hand in the direction of your right shoulder. In this manner, you are asking the horse to give his nose to the inside, while keeping his shoulder elevated. Then use your inside leg to push him away from the barrel, or use your outside leg to push him closer. Legs, legs, legs!
∞•*˚ Βгįťţαňγ ˚*•∞
It is not enough to know how to ride; one must know how to fall.