In the example of the Constant Offset reshape, it is natural to want the offset path section to extend from the original path at its original angle. This is where “Smart Joining” provides a solution. With Smart Joining enabled (by clicking the button on the panel), Reform will, when possible, try and extend the path section while keeping the path's original angle:
Reform Smart Join Option
When dragging out a constant offset, you can toggle Smart Joining by pressing the S
key. The Smart Joined extension is always straight, even if the path is curved.