Yes i know that !ODE accumulates the feedback, and doesn't split them along individual axis. Are you happy with the dJointFeedback from ODE?
In fact we have to project the force/torques along/around joint's axes in order to get a valid information for 1 particular joint axis.
It is not a problem : we have already done that for our ODE based engine.
The most important is to have the same mechanism (units, body1/body2, force+torque), if possible, in order to allow old-ode users to switch without so much problem.
Many thanks