This is a MKII version of an earlier design. It has two notches to receive the end of the film onto the core, and because of that, it needs supports to print. The earlier version has no notches but can print without supports.
I like to put the 3D printed cores on the take up side in case they accidentally go to the lab and I don't get them back. Normally I don't like to tape film to cores (might gum up the works later) and hence I designed these notches, in a practical applications, I punch out the core of the take-up after it is downloaded and replace it with a conventional type U core so lab doesn't have an issue. When I do that, the tape vs notch is not really an issue. the MK1 is easier to print and clean up, the MKII is a bit more versatile.

Prusa

i3 MK2S

Doesn't Matter

Yes

This MKII needs supports for the notches for the film. If you prefer to attach film to core via tape, you can print my earlier design without notches that prints cleaner without supports.