For XPSWMM and Infoworks (any GUI editor you have actually):

Moving an existing line substantially is something that occasionally happens. If we could do this without having to delete the entire thing, or click and drag each vertex one at a time, it would be a big help at times.

A new feature I’d like to see for lines/polygons is a ‘realign feature’ tool. When selected, if you clicked on a vertex in a line or on a polygon boundary (single click and release), it would ‘grab’ that vertex and allow you to move it. Once you place it by clicking, when you move the mouse either direction along the line, it would AUTOMATICALLY grab the next vertex on the line. Right-clicking would bring up a menu allowing you to ‘release’ the line (leaving the ‘grabbed’ vertex in its original location), delete the grabbed vertex, insert a new vertex, or ‘skip’ a vertex and move up/down the line. Once you deleted the vertex or inserted a new vertex, it would again automatically grab the next vertex either direction based on the mouse movement.

At least at first, when you select the tool, it would be good to have a window explaining how it works (with a checkbox to make it stop appearing).