Subtraction vector points artifacts

[handrawn]

you need 'convert line to shape' Ben

ctrl+shift+S is 'convert to editable shapes' - works on quick shapes and text etc but not on unclosed lines - there is no standard key shortcut for 'convert line to shape' but you can set one in pro version

[RE-EDIT - I get what appear to be inconsistant results using ctrl+shift+s ]