Thank you. Inertia Tensor Scale is the one you want.
You need to have a few things set up for the picking up of a ragdoll.
Mostly substepping.
Max Deltta Time: 0.016667
MAX Substeps 6.
quick example:
And settings to go along, as I had it open.
Not sure what the defaults for Damping are, but all my limbs are set to .01linear, and .0 angular.
The other important settings MAY be Enable Projection and a Linear tolerance of 5 on the constraint. Those too seem to be Default values however.