Unlike any other actor, you cannot manually set the location of a builder brush in the Details panel. Whether or not this is a bug, I don’t know, but now it’s here.
This becomes a huge problem when using a brush to specify a pivot point when creating static meshes in the editor, as you cannot snap at anything below 1 unit and can’t specify the position in the Details panel, but have to rely on the translation gizmo.
This post was marked as resolved for tracking purposes as this feature is currently under consideration. Please keep a look out for updates in the future.