I've added it, but not really sure how helpful this set will be... the usable bits range from 1.8 - 2.0 - 2.35 - 3.0

Normally, folks like to jump in 0.1mm increments and these are the types of sets that most folks are gonna be interested in buying, i.e. Ryan Lutz's setup sheet calls for a 2.1mm bit, so that's what I would personally like to see included in a set that I would consider buying.