When I’m painting with the regular pencil tool, I often want to draw straight lines.
I’m using the shift key to use the line tool in quick mode. It’s very handy.
It would be even more handy if the line tool (when used in quick mode) would keep the same brush size as the pencil tool.
When pressing Shift while using the Pencil tool to draw lines, it already keeps the brush size of the pencil tool. Are you talking about something else?
The shift+pencil thing is a little unintuitive. You have to have drawn something with the pencil, and after that, if you hold shift and move the cursor (without clicking), you can see a preview of a straight line from your last stroke to where your cursor is. You click again to place the line.