Just kegged and carbonated (lightly) an Irish Stout, but it’s tasting kind of low on flavor…

I’m thinking of adding oak or coffee beans (or both) in a bag in the keg to try and add some more flavor.

Please either talk me down, advise on amounts and time, or advise me on better options!

It’s good enough that I wouldn’t toss it, but not good enough for me to not want to save it…