Any rig with deform bones and a mesh skinned through an Armature modifier: Mixamo, UE5, Rigify deform bones, glTF characters, quadrupeds. Bone names do not matter; the bodies are chosen from the skin.

The wizard needs thirteen bones dragged into slots and gives every character the same capsules and limits. RagdollForge fits the shapes to your skin and reads the limits from your animations, so the character does not snap when it goes ragdoll mid-animation.

On the UE5 mannequin with four animations, 135 of 146 poses were held in Unity with no movement at all; the other 11 (the left elbow in an attack) settled by up to 16°, and the panel tells you this before you export.

In Unity 6, 24 falls of four characters, six different pushes each: every one came to rest, joints stayed within 18 mm, resting penetration into the floor at most 2 mm.

Unity in this version. The ragdoll file is plain JSON if you want to bring it elsewhere.

No. The shapes are wireframe preview objects in their own collection; Remove Shapes deletes them. The ragdoll data is stored on the armature.

No.