Add page sizes as per calligra
Planned to mention this before: screen is not something intuitive, how about removing it?
That's true, unlike LO Writer, LO Impress has Screen 4:3 and other sizes because Screen is the target medium for presentations.
For us it can be too but it's not clear what orientation and what screen do we mean. Power users have custom size to easily apply screen geometry if really needed.
Calligra has no envelope types, Qt has, and our users may need it. How about appending:
(grabbed from LO, it must be that they picked most popular on all OSes)