Rotax 912 Choke Spring Wear on Choke Lever Arm

We are all familiar with the Rotax 912 throttle springs. Note that where they hook into the throttle lever arm, there are little plastic sleeves in the lever arm hole to prevent wear. There are two different sleeve sizes, part numbers:
963015 - on the Throttle Valve Lever (Top of throttle spring)
963010 - on the Cable Support (Bottom of throttle spring)

There is a similar spring on the choke (starting carb). However, it does not have a little plastic sleeve fitted. Nor do I see one on the diagram in the Illustrated Parts Catalog. The top of the spring goes into a pretty sturdy place on the Chamber Top. But I am noticing a tiny bit of wear from the spring hook (bottom of spring) to its hole on the Choke Lever arm.

Anyone else see this?
Should we retrofit a sleeve?
If so, which sleeve type (if either?)
Or another idea?

I have not seen this to any degree that would concern me.

Two questions I always ask when someone mentions something like this.

1. Do you know for sure that you prop blades are at the same pitch value (with 0.1 degrees of each other)?

2. Have you had a dynamic prop balance done to see if there is a solvable imbalance?

They were at last annual. Engine runs smooth. Only the slightest wear on one of the carbs - not a "notch" cut into the hole (yet...). That bracket below the ignition modules (mentioned in another thread as a possible victim of vibration) is fine. Plane has 190 hours.

Just seems unusual those don't have a sleeve. I was thinking about using a small piece of brass inkpen-refill tube for one.