Blocking ETRD with INSL works on every distance. Just that the INSL needs to be on the direct line from one ETRD to other, for example try Shift-dragging from one etrd to other.
@disturbed666(View Post) I imagined the same thing with the heat (before i read this), weight , velocity etc. and I think there should be one way wall too example:allows the particles that come from right, blocks the particles that come from left