First thing first, what is a carrying angle? It’s a small angle between the humerus and the forearm. It’s easy to check if you have one. Stand in front of a mirror the arms alongside your body and externally totate your arms (savasana arms) Some of you will have the arms straight by their side, and some others (like me) will notice that their forearms and hands are moving away from the body, their arms have like a boomerang shape. This is what is called a carrying angle.
Having a carrying angle will still allow you to practice yoga, but some modifications need to be done in some weight bearing + arms straight poses, mostly to protect the wrists that have a tendency to be weaker when the arms have this shape, and the shoulders.
You have guessed that the postures the most affected by this “condition” are Adho Mukha Svanasana (down dog) Adho mukha vrksasana (handstand), Urdhva Danurasana (wheel) plank…
In Down dog, the common cue saying that the eyes of the elbows should face forward will cause some problems, because arms won’t be straight whatever you will do. This is due to the bones shape at the elbow. So if you apply this cue you will lose the external rotation of the shoulders, and therefore you will lose stability in your shoulders, and that’s precisely what we are looking for in adho mulha svanasana, stability in the shoulders so you can practice jump to handstand or the down dog plank chaturanga vinyasa (which i bet you practice quiet often) in the safest way as possible.
What will help is to strengthen your arms to hold the asana in the strongest way. When the bones are perfectly aligned it helps to carry the weight without too much effort, the stress of the weight is absorbed by the alignment of the bones, not by the muscles. But, if you have a carrying angle, the alignment of the bones is structurally impossible, so you will have to compensate with the muscles, to make sure your posture is still stable.
It’s a good idea to have the upper arms a little bit more closer to each other than the usual, and the hands slightly externally open (fingers pointing to the external side of the mat, (not too much!))
The strong fondation of the pose (down dog) will come from the triceps and the rotator cuff. You will have to pull the upper arms towards each other, and pull them tin the shoulder sockets. This will help to create the line of energy, that will push your sitting bones back towards the back of the room; and you will feel the stretch that you look for in Adho Mukha Svanasana. The same modifications can be apply to the handstand, or wheel pose or any weight bearing + arms straight pose. (Yes even Urdhav danuradana, where the carrying angle can be an obstacle to the opening of the arm pits, and the work of the shoulder blades)
On the other hand, some asanas are easier for people with the carrying angle, like Salamba Sarvangasana (shoulder stand) or Mayurasana, the shape of the bones will helps to place the forearms or elbow more easily.
Do not hesitate to talk to your teacher about that, Every body is different and taking some smart modifications will help you practice until 100 years old.