Lets examine some of the images from Cirque de Soliel to think about how to represent what is going on in D&D.
First and foremost, these are mostly Charisma (Performance) skill checks. They do reliable, low-risk actions, that they can repeat for multiple performances, that are visually appealing.
Here is an awesome picture of two contortionists. Neither is especially using Strength, but the visual effect is beautiful to me.
In this picture, the two women are mainly doing contortion, folding their bodies. Neither is using Strength. Contortion is slow, precise, movements and arguably uses Dexterity. Currently, their bodies are moreorless stationary, standing in a still poise, moving slowly, and non-agile.
Here are two other contortionists. The one that is doing the handstand might be using Strength for it, but is stationary and non-agile, and is more likely using her Dexterity for the small precise movements.
So, probably all of the contortionists above are using Dexterity for stationary small slow motions. They seem to neither use Strength, nor be ‘agile’.
By contrast, compare performers from Cirque de Soliel who are doing actual ‘acrobatics’ - from a trapeze. These two are gymnasts, strong, and this case using their Strength for weightlifting, body lifting, and climbing.
Also here is an image of what D&D ‘tumbling’ might look when it lacks Strength, and only uses Dexterity to finesse the bodyweight. Notice, during this aerial cartwheel, her head is less than a foot above the ground. There is no highjump. Without the highjump, she can substitute Dexterity instead of Strength.
