MCF8315A: Negative currents

I had previously asked how to command negative current using i2c commands (https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1251320/mcf8316a-torque-control-mode/4769937#4769937). The suggested solution kind of worked, but it seems to respond only at very low and inconsistent update rates. It is not sufficient for closing a control loop and mostly ignores the setpoints. I had to revert to using only positive current setopints but need to revisit this issue. Please suggest a way of sending positive and negative current setpoints that are accepted and tracked at an update rate of at least 50 Hz.