Due to the length of the bristles (default brush), when the carriage lifts to reink, then sets the brush back down to complete a given line, you are left with a gap in the line that does not get painted.
This may be acceptable for shorter bristled brushes, pens, pencils, etc., but i believe it would be a "nice-to-have" option in the WCB extension to backtrack from the reink point % (var.) inches before setting back down. This should close the gap.