Bug - Master Properties and toComp() expression
Most expressions linked to a Master Property work properly when the MP is changed across different instances, but a few expression methods like toComp() and fromComp() always act as if the layer being referenced has its original transform data, even if those properties are being changed instance-wise by the Master Properties.
For instance, if in "Comp 1" I put a Beam effect, using the positions of two 3D layers as the endpoints using toComp(), and control the positions of said layers via MP's in "Comp 2" (or control the "Comp 1"s camera position, etc.), the Beam endpoints just stay in place on any nested instances in "Comp 2".
Kevin McCurdy commented
MP's also don't seem to affect 3D-enabled effects like CC Cylinder.