Although there are many criticisms, it seems that the intended purpose is wrong. If you use it without hitting it locally, you can almost recover it. If you use it extensively you should choose a tool for it. I do not know the durability, but after a long absence at my workshop? It was a hit item.
If you press the nozzle against the base material it will certainly be a paint film, but if the range is 2 cm ... It is impossible to expand the irradiation range by slightly separating the nozzle from the base material. Since it is not necessary to return the abrasive, if it can not kick a wider area it will not be usable.