Beam portal
This scripted entity is designed to portal the beam trough itself when a unique exit entity ID is provided and its model is the same as the one the beam enters.
The entity will be turned on whenever the input beam hits it. If there is no beam present, this means the input beam is not in sync with the surface normal vector of the portal. If the vectors are in sync when the input beam hits the proper surface of the portal entity.
The output beam behavior and visuals ( texture, sounds, color, flags etc. ) will be taken from the beam source entity from the current hit report. The portal can process recursively many beams at the same time.
This entity has only one input that is the normal local surface vector and some outputs for information.