I'm not sure of why Efke's film would be cut to paper sizes, but their direct positive paper is cut to the print size spec of 4"x5", NOT the film-size spec of the "4x5" format, which is actually in metric, and is a bit less than 4"x5". As one who uses a lot of paper negatives as film, and who has also used the Efke direct positive paper, I purchase the 8"x10" print paper and trim it in the darkroom with a rotary paper trimmer, setup with presets for the length and width cuts so it can be done accurately in the dark.
Remember: 4x5 paper is generally 4"x5"; "4x5" film is NOT 4"x5", but a bit less (an ISO spec.)
~Joe