I think the above values must be corrected and are axis to obstacle, no outer surface to obstacle ... otherwise the micropiles would not be as close as we use to see them in wall applications.
"For a vertical micropile, the micropile centerline can be located within approximately 375 mm (15 in.) of the face of an adjacent wall. This distance may need to increase for micropiles larger than approximately 175 mm (7 in.) in diameter."
As said above, they can be placed even tighter to the wall obstacle (I have seen it), but the installers won't do usually except when under designer's pressure, and simply in other cases they can't (without supplementary defacing works). If one is not following closely the question, installers quite likely will drift to cozier tolerances, placing the micropiles 20" axis to wall or so, average.
To a large degree it depends on the drill rig being used. Some can get a lot closer than others, but 10" is a decent starting point for a smaller indoor rig.
