Gargoyle Stoneplate's interraction with True Damage on Camille

Hello.

As I was messing around with Camille in a custom game, I happened to notice her 2nd Q true dmg was being reduced while under the effect of Gargoyle Stoneplate's active.

While the active description states that damage dealt will be reduced by 60% for the duration, I don't think true damage is ever supposed to be affected by damage reductions. Also, there are multiple clips where you can clearly see Cho'Gath's ult damage not being gutted whatsoever. I've tried other true damage abilities such as Vayne's W or Darius' R under the effect of Stoneplate active and the damage was not reduced either.

I would really like this issue to be adressed for the sake of consistency.

Thank you very much for your attention.