I was referring to your claim that there are "effects of local preparations at positions light years away". This is a claim on the dynamics. The paper of Hegerfeldt is no surprise. It's known since the first attempts to generalize Schrödinger's successful formulation of wave mechanics to the relativistic realm. It's well known that this fails for exactly the reason we discuss here. That's why in the 21st century relativistic QT is introduced right away as relativistic (microcausal) QFT (see e.g., Peskin/Schroeder).