How to Retarget an Animation_BP without breaking references?

I have a BP_Character1 that uses [Cast To BP_AnimOld] to access an Animation Blueprint’s variables
(i.e. to Get/Set its values).

Later, I needed to update character1 and that required retargeting to update all the referencing animations.

There were 20+ animation sequences associated with character1 which would have taken a while.
However, I noticed that if I retarget the animation blueprint then all associated animation sequences and blendspaces would also be retargeted (generated) automatically. This was a faster solution so I used it.
This process creates duplicate assets and I thought that was ok but now I’m not sure.

Retargeting the animation blueprint also generated a new copy, i.e. BP_AnimNew.

As mentioned earlier, BP_Character1 used [Cast To BP_AnimOld] to access its variables.
If I now want BP_Character1 to (instead) use BP_AnimNew that’s fine, but that means
all previous references and uses of [Cast To BP_AnimOld] must be replaced.

That is my problem (see screenshot).

There are so many calls to [Cast To BP_AnimOld]->Get/Set(variable) that it takes a while to replace all the nodes and wiring.

Is there a better/easier/faster way to retarget a character without having to update all the old references?