Looking near or inside a Warden can cause performance issues in Vibrant Visuals

In the 1.21.120.20 preview, a change has been made where mobs now render partially transparent when the camera is close to them. This doesn’t appear to cause any performance issues for any mob except for the Warden, where you can see the FPS gets cut in half on my Windows computer with Vibrant Visuals (favor performance) enabled. However, on my iPhone 11 Pro there appears to not be any performance issues with the same settings and flat world environment. Performance is not affected on either device when getting close to a Warden with “fancy” graphics.