Thanks for the suggestions. I have grape seed and canola readily available. I also have almond (I thought I was ordering almond FO, but it was actually oil, oops) which I believe I read somewhere goes bad easily.
So I think I'll make a few mini batches of a few different types, and split each batch so I can have some with and some without the anti-oxidant.
When do you typically add an anti-oxidant? A guy I work with who has a PHD in chemical engineering said I should add it after the lye, so probably when it gets close to trace. The problem with the stuff I have is that it is in solid form, so I need to pre-dissolve it in something. Unfortunately it's not water soluble, but it looks like it dissolves in warm oil, so I will have to go that route.