Has anyone made Dorie Greenspan Bubble top Brioche. She says add butter 1 T at a time, then 4 minutes. Is that 4 min total or 4 min after each add?

I use both with good results in both taste and texture.
Generally, use what you have, can find, can afford.
I seem to remember reading that unbleached is safer, healthier in long run, but I haven't checked it out recently.
You might want to look into that.

Thanks Nancy you've been a big help. Since you bake often do you have any suggestion re; unbleached or bleached flour when baking brioche or challah?

Reading the recipe at Bon Appetit or Epicurious, and having made brioche, my suspicion is 4 min total (to add the butter in 1 tbps increments).
Then there is more beating (8 or 9 min by machine) until dough pulls away from bowl.