XOrigin on new relation table

Hello,

My goal is to mirror changes in adsgroups to associated ldapgroups. Please let me know if I have missed a better way to do this, but here's my plan:

I am planning to create a 'join' i.e. 'M:N' or 'relation' table to record the associations, but am unsure if in the future I would have use for the XOrigin column, that is offered during table creation in the Schema Extension.

If this is the way to go, could anyone advise whether it would be possible to add the XOrigin column later, if needed, or if I should create the table with the column even if I don't intend to use it for the time being?

Thanks!