Video in the elevator does not work after update
Following your instructions I was able to run the elevators and video work perfectly if I start the map from Hammer or file namemap.bsp.
To be safe I changed the names of the files I changed:
my_video_splitter.nut
instances/turbine_elevator/arrival_elevator_a4_logic_mod2.vmf
instances/p2editor/elevator_exit_mod.vmf
instances/p2editor/elevator_departure_logic_mod.vmf
I have included all the files in the. Bsp with Pakrat and I published the files on workshop with p2map_publish.exe.
I downloaded and installed the map on Portal 2 and I removed the file my_video_splitter.nut.
Videos are not seen in the elevator.
I do not know, obviously I could not use because Pakrat the file. Nut does not seem integrated. Bsp

with pakrat not been able to integrate the old video_splitter.nut
If I replace with the new, work in the workshop videos randomly ignoring the requests of the given video in instances/p2editor/arrival_departure_transition_ents.vmf
PFEW 
There would be no other way than to attached the new "my_video_splitter.nut" with the bsp and tell players to place it in its right folder before playing the map.
... That or make a portal2_dlc3 new folder to place all the custom stuff there... This folder will be taken by the game as the main path, then dlc2, then dlc1, then portal2...
Referenced Links:
http://forums.thinking.withportals.com/mapping-help/packing-bik-and-scripts-with-pakrat-t5839.html