When playing in second position, the route note is the three below and the two drawer. So the route note would be an every cord up the harp on the blow notes, but would also be included in any of the cords that contains the two draw. Is this especially significant? Does it make cross harp better for the I, IV, V blues progression?
It seems that your auto-correct function has gone wild in your post. I assume that your question is:
"When playing in second position, the root note is the three blow and the two draw. So the root note would be in every chord up the harp on the blow notes, but would also be included in any of the chords that contains the two draw. Is this especially significant? Does it make cross harp better for the I, IV, V blues progression?"
Here is information showing some diatonic harmonica chord and partial chord options. The idea of partial chords and arpeggiated chords is important, too.
In addition to the linked page, also check out the "Arpeggios" link at the bottom of the page!
I think the so called "Richter" layout was designed for playing 1st position chords and melodies, but the layout is very useful in 2nd position, too. Many of the chord and partial choices may work in different positions depending on the music. I am guided by my ear, but this kind of information can help you discover new possibilities. ----------