I get my POTC LE next week and therefore follow the slingshot/clearcoat issues with interest. Some thoughts from my side:
1. The whole issue is due to a bad construction of JJP. The playfield should have small holes in the playfield, in which the posts sit, so not on the clear, but in the wood. That would have prevented chipping even with sharp small posts. My Stern ST has this in the slingshot area.
2. The role of the slingshot plastics is not yet discussed. These plastics at least assist in the stability of the posts, they might be able to prevent strong pressure inwards from the sling movement if the plastics holes are properly drilled (without major space). Assuming that the chips result from the slingshot pressure inwards, a plastic can avoid this pressure if put on with slight pressure to the posts outwards (as a counter pressure to the sling pressure during gameplay). I will check the plastics when getting my LE and think of adding a clear hard plactics piece under the JJP plastics with individually drilled holes to create this counter pressure.
3. The whole group of slingshot posts are not constructed very well, because the cover plastics are connected with 2 posts only and not to the third, which has to bear the inward pressure without plastics counter assistance.