The first solution is not working, because overrideAlpha is used for blending bone.X and bone.Y position to the transform position, if you directly set bone.X and bone.Y you bypass the blending effect of overrideAlpha. The respective code parts can be found here for better understanding:
spine-runtimes/SkeletonUtilityBone.cs at 3.8

However, your second solution is expected to work correctly. Are you perhaps encountering other problems or side effects? You can have a look at the example scene Spine Examples/Other Examples/SkeletonUtility Animated Physics and change the Override Alpha value of Head and Neck via the Inspector - there you should see properly fading bone override intensity. Is it reacting in any way in your problematic scene when you modify the Override Alpha value in the Inspector?

Could you show us a screenshot of your hierarchy of SkeletonUtilityBone GameObjects? Are there perhaps other parent GameObjects that are interfering or having other overrides active?

Thanks for posting the bone hierarchy.

Just to be sure: I assume that you have not re-parented any of the bones, but please note that SkeletonUtilityBone does not allow for simple reordering in the hierarchy (you would need to explicitly set the Parent Reference parameter in the Inspector).

MommysBestGames wrote

Basically, once, I changed the transform on the "BackHandHold" in the scene view, (it was 0,0,0), the bone would follow the animation, but also be moved up in the air (if for instance, I moved it to (0,1,0).

A few questions regarding your setup:

1. What are the Inspector properties of the BackHandHold SkeletonUtilityBone component, did you set it up to follow both position and rotation?

2. Does BackHandHold behave as expected when you set the Override Alpha parameter to 0 or 1 via the Inspector and disable any of your code?

3. Does the bone follow the Transform correctly when Override Alphais set to 1 and you move it around via dragging the Transform around in the Scene view?

4. Does the IK bone sertup work as desired when you test it in the Spine Editor?

Apologies if you already answered part of the questions and I misunderstood your description above.

MommysBestGames wrote

3. If I set override Alpha to 1, I can drag the back-hand IK around, and it follows the transform, HOWEVER (and this may be a clue!) once I move the transform, and offset it some, I can't get it to follow the gun again.
If I set override Alpha to 0, it stays stuck, just where I left it.

I fear that we will not solve this problem via a forum discussion alone.
Could you create a minimal Unity project where this problem still occurs and send it as a zip file to contact@esotericsoftware.com? Then we can have a look at it.

We received your email, thanks for the reproduction package. We will have a look at it and will get back to you as soon as we figured out what's going wrong.

I think I know the cause of the problem:
Your animations do not change the position or rotation of the hand (or the IK target bone) at all, relying on the initial setup pose position. Now when you change the position via an override, no animation track will reset this value - thus it stays as is.

You could either add some position and rotation keys in the idle animation, or maybe as an alternative reset the skeleton to setup pose via code as follows:

else
{
    backHandIKGrab.overrideAlpha = 0f;
    this.GetComponent<SkeletonAnimation>().skeleton.SetBonesToSetupPose(); // replace with nicer code / cached SkeletonAnimation and don't call this every frame, only upon switching from holding to non-holding.
}

That worked when I tested it.
Please let me know if that resolves the problem for you as well!

Thanks for getting back to us, glad to hear it works now!