I doubt that you could even get a broadcast facility to accept a 55 sec. spot. Must commercials are sent via FTP sites and many are automated when spots are uploaded. If your spot is anything but 60 seconds to the frame, it will likely be rejected just for that alone.
I’ve never heard of anyone trying to air a 55 second spot. It makes no sense and no broadcast station is going to have a 55 sec. slot to run it in. It would require them to, at the very least, fill in the remaining time with????
Tell your client that it’s a dumb idea…nicely of possible.
Not my monkeys. Not my circus.