I have a rig that is not a typical L/R biped. It has N/S/E/W limbs. The limbs have fairly complex rigging that I'd like to avoid having to individually animate. Without the mirror functionality, is there a way to copy action keyframes from "east bone X" to the corresponding north, south and west bones?
Try this. Change your Timeline at the bottom of your screen to Dope Sheet. Next, select the keyframes from your east bone X and duplicate them to your other limbs. You should see under the Dope Sheet Summary each of your limbs. This has worked for me when I need to copy my animations to other limbs. Hope this works for you!