valueAtTime leaks across Essential Graphics instances

Using `.valueAtTime` in an Essential Graphics instance incorrectly returns values relevant to other instances, in what looks like cache collision.

This bug is preventing me from migrating my project from an older version of After Effects (23.5), in which `.valueAtTime` and Essential Graphics reacted predictably together.

Exact steps to reproduce:

• Create a composition with a visible layer inside it.
• Add a Checkbox Control to the layer.
• Link the layer's opacity (or other visible property) to the checkbox like this:
  `100 * effect("Checkbox Control")("Checkbox").valueAtTime(time - thisComp.frameDuration)`
• Add the checkbox control to the Essential Graphics panel.
• Drop two instances of the composition into a parent composition.
• Add some keyframes to the essential property on both layers, toggling it on and off.

Expected result: Each instance is animated according to its own keyframes, with a 1-frame delay.
Actual result: The two instances interfere with each other, and a keyframe on one layer causes the other to change in an inconsistent manner.

Affects the current version of After Effects (26.3).