If you want a powred ragdoll, the exact solve is what you want. the iterative solver does not have the converge rate to produce a hard reponce in one frame.
The future that can select solver based of the contacts is on core 300, you sync to svn and just swap library is should juts works.
then you get the best thet the engine can offer, more resposive rag doll, bu also fast scene.
The one thing I mention to you is that what you wnat to do is not matamatcailly possible. you cna no make a joint the can rotae independllly aorudn three angles.
the is what the Euler and Shoemake theorem demostrate, three euler rotation are equivalent to a single rotation around the shorter spherical arch.
so there are not three degree of fredomn ther is just one.
There one thing that you can do is to use an approximation that states "for small angles the the product of rotation matrices commute"
that is: say you have a matrix, you can decompose ther matrix into tree angles, pitch, Yaw, Roll, the you you get the
matrix = picthMatrix * Yawmatrix * RollMatrix;
however teh solev will not take lareg angular stepe, it will talke smale steps like this.
1) Matrix = matrix1 * mnatrix2 + ... != (picthMatrix0 * Yawmatrix0 * RollMatrix0) * (picthMatrix1 * Yawmatrix1 * RollMatrix1) * ....
and that so the problem, the path is just incorrect sinc the corrent identity is
2) Matrix = matrix1 * matrix2 + ... == (picthMatrix0 * picthMatrix1 * ...) * (Yawmatrix0 * Yawmatrix1 * ...) * (RollMatrix0 * RollMatrix1 * ....)
this is what you can do, ther is a Leman teh say that the product fo tow euler is comutative is the angle are small.
so if you dicide you angle into a series of small sube angles.
then you cna say that
Matrix = matrix1 * mnatrix2 + ... == (picthMatrix0 * picthMatrix1 * ...) * (Yawmatrix0 * Yawmatrix1 * ...) * (RollMatrix0 * RollMatrix1 * ....) == (picthMatrix0 * Yawmatrix0 * RollMatrix0) * (picthMatrix1 * Yawmatrix1 * RollMatrix1) * ....
only when:
if picthMatrix0 = picthMatrix1 = .. = picthMatrix / N == a small angle
if Yawmatrix0 = Yawmatrix1 = .. = Yawmatrix / N == a small angle
...
in fact that is the procip[la assumetion that it is use to demostrate teh Euler Shwemeke threrem.
so basically what you do is to make a joint that solves for the tree angles but intead of usin the full angle you use a fraction of the angle, and you run the solve N times.
That will Guareantee a amost 100% accurate Euler rotation Joints whe the three angles are independet.
even the iteratove solve can deal with with that,
I hope that is clear.

for Newton Core300 I was planning to make an anymation systm with a pweful IK system which at teh core will have that Joint,
bu I iwll ahev to make a minisolve that will take care of th sube steps in insulation.
That joint can make if possible to have Perfect Arm Socket and Femul socke joints for alticulate bodies that can be controll at will.