Is it safe to create add new column in direcut_user table ? also will it have any impact while migrating to major version e.g v1 to v2

is it safe to create add new column in direcut_user table ? also will it have any impact while migrating to major version e.g v1 to v2
and how do we version the core table so that we know which table are modified before we deploy the major version to production
want to know the best practice to follow
As i have requirement to add more fields to directus user table so i am not sure if i can do this ..
thanks