Some of the lettered bits are the perfect size for taps, if you are really concerned about the per cent of threads you wind up with. I was looking for replacement chucks on eBay a couple of years ago and some of the smaller chucks were down to very small sizes. The 1/2" ones usually only went down to a 1/16 minimum. There were chucks that were worth $1000 there but I doubt any of us need that kind of accuracy. As far as I know NASA isn't making parts out of wood.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.