I made a free addon for Blender to replace the manual use of Sequencer’s Snapper Tool for the simple act of snapping your IK bones to their FK counterparts. It’ll do any number of animations in a single batch in Blender, and auto export them as it finishes them. Takes ~2 seconds per animation on my PC due to the import/export process.
Above is a video detailing how it works (link to the addon on gumroad is included in the description), and how to follow up by resolving 3 of the most common issues in Unreal’s reimport and retarget process.
This should turn hours of repetitive stress injuries into a few clicks and you’re done.
Warning: This addon does not preserve weapon offsets. It will snap the ik_hand_gun to the hand_r. As the video states, it only works with default unreal bone names and only if your ik bones are intended to match orientation to their fk bone counterparts (if rotation is mismatched intentionally, this won’t work for you.)
Video is here, includes link and instructions, plus the previously mentioned common troubleshooting tips for the process as a whole:
I never intended to publish this, so while it works perfectly fine, try not to actually read the code, as it might embarrass me: I simply wanted an automation assistant to save my mangled hands from the dreaded Snapper.