First thing I see is that you shouldn't read the quaternion in reverse order.

Also you shouldn't use glm::mix, use glm::slerp instead.

And here is how I construct the bone transform:

mat = glm::mat4_cast( currentrotation );
mat[0][0] *= currentscale.x; mat[1][0] *= currentscale.x; mat[2][0] *= currentscale.x;
mat[0][1] *= currentscale.y; mat[1][1] *= currentscale.y; mat[2][1] *= currentscale.y;
mat[0][2] *= currentscale.z; mat[1][2] *= currentscale.z; mat[2][2] *= currentscale.z;
mat[0][3] = currentposition.x; mat[1][3] = currentposition.y; mat[2][3] = currentposition.z;

Also I would check all my matrix multiplication, it should be in reverse order to how would you do it with Assimp matrices.

I base all this on personal experience from implementing an animated mesh with assimp and glm myself.(which now works) But it might not be the correct way of doing things.

First thing I see is that you shouldn't read the quaternion in reverse order.

Also you shouldn't use glm::mix, use glm::slerp instead.

And here is how I construct the bone transform:

mat = glm::mat4_cast( currentrotation );
mat[0][0] *= currentscale.x; mat[1][0] *= currentscale.x; mat[2][0] *= currentscale.x;
mat[0][1] *= currentscale.y; mat[1][1] *= currentscale.y; mat[2][1] *= currentscale.y;
mat[0][2] *= currentscale.z; mat[1][2] *= currentscale.z; mat[2][2] *= currentscale.z;
mat[0][3] = currentposition.x; mat[1][3] = currentposition.y; mat[2][3] = currentposition.z;

Also I would check all my matrix multiplication, it should be in reverse order to how would you do it with Assimp matrices.

I base all this on personal experience from implementing an animated mesh with assimp and glm myself.(which now works) But it might not be the correct way of doing things.