Hi.
I expect the brush to match the topology to the scan.
Looks like RelaxProj brush performs like a smooth brush.
Link to the video.
I was just having the same problem, but I have found that it only does this if you have transformed (scaled) one of the meshes. Try saving out an intermediate copy of the scaled/transformed mesh, then load it in with a new LoadGeometry node to feed into the Brush node… hopefully that will help.