Oak Cube question

I have a recipe copied from online from John Palmer that states 3 ozs of America Oak Cubes, medium toast, added to the keg for two months.

I assume if you’re bottling that you would want to add them after two weeks for primary fermentation. But rather than racking over the primary to a secondary fermenter, would it cause a problem to simply add the cubes to the primary fermenter vessel after the two -week period for primary fermentation and then allow it to finish there?

Thanks in advance for your advice.

I don’t normally secondary, but for aging I do. Anything longer than a month I’d secondary just to be safe.