WWI Career Mission types

[Napping-Man]

If I wanted to spice things up a bit in the Western Front WWI Career, would it be possible to add mission types such as 1121 = "Area patrol" without breaking anything?  I wanted to have more missions where Allied (Entente) are flying Patrols behind the lines much more often.

 

Are there mission types that only work for WWII Careers?