From https://superuser.com/a/1116541/1744807.
/internal
calls the internal screen (your primary display)/external
changes to the external screen (im not sure how well it handles when there is more than 1 screen)/clone
duplicates displays./extend
switches to extended settings.
C:\Windows\System32\DisplaySwitch.exe /internal
C:\Windows\System32\DisplaySwitch.exe /external
C:\Windows\System32\DisplaySwitch.exe /clone
C:\Windows\System32\DisplaySwitch.exe /extend