Hi Brian,

re:
> Is there a way for a script to tell if it is running in MoI3 or MoI4? A version tag or flag?

Try moi.majorVersionNumber, that will be a numeric value of 3 or 4 for v3 or v4.

There is also moi.version which returns a longer string like "4.0 Beta Dec-12-2017".

- Michael