When I build Arm_2jnt_04 with 1 division in elbow-wrist part and with “Mirror IK Ctl …” and “Align wrist to …” options both checked there is a bug with the middle joint in this area (arm_R0_3_jnt in such setup). It doesn’t align properly and rotates in all directions with arm movement.
This problem is on the right side only. The left side works as intended to. The problem stays when I build the rightside from scratch and when I duplicate from the left side as well.