It's always a treat to come across a function you haven't used before, especially when it does exactly what you need. While reviewing chartfield configuration during an upgrade, I came across the delivered function BulkInsertField. I found it in the chartfield configuration app engine FS_CFUPDATE and it came in handy.
I'll leave the details to PeopleBooks, but essentially it allows you to add a field to pages and records. You supply it with two fields: the field to add and the field that you want to use as your model (what record should it come from, what should the page field properties be). The insert works especially well with grids. The function runs over a project, so you get great control of which pages / records are updated.
With a one-step app engine of my own, I was able to quickly add three fields to a number of pages and record. It was the perfect tool for the job.