Yes… Create 2 separate curves (splines are just a series of curves - see below). select mirror by line. Select the curve and the 2 points A3 & A2. Select the 2 points for the mirror line A5 & A4. Add a line between A3a1 and A2a1. It should be noted that “lines” in draft mode mean nothing in piece mode. They are only there in draft mode as a visual reference. Piece mode only works on point nodes and curves… it creates paths using the nodes and curves. A line is simply the (straight) path between 2 nodes.
That being said… would it be useful to be able to select lines for purposes of operations and piece selection? Perhaps. Off the top of my head it would most likely require some refactoring the line class as it lacks some of the sub class info that the rest of the tools have. Not sure why the choice was made to not make it the same as the rest of the tools, but [fill in blank]… water under the bridge, spillt milk, etc.
Just a note… they’re ALL bezier curves. The only difference is how the control points are defined. The Curve w/control points uses draft block points for the control points, where as the Curve tool uses user defined control points.“Splines” are just a series of consecutive curves. In theory we could really eliminate the curve tools as they are just the spline tools used once… or more specifically the spline tools more or less just repeat the curve tool until you press enter.
There is. Point along spline. If you want a point between for A1 & A2 along the SplPath_A6_2…Select the spline. Edit the formula to take the spline length of the 1st segment A6 to A1 and then add what ever distance from A1 to A2 you want. Here I used 1 inch to cretae point A7.
That being said… It’s always possible to add tools (as opposed to features) , the question is whether a tool is worth the effort. It takes a lot coding to add a new tool. If it doesn’t have wide appeal it’s not worth the time - at least not my time - to add it. I’d rather add tools or features that are really needed - such as support for symbols and buttonholes to name a few. Or maybe a “fold out” tool to create a hem on say a sleeve… which is what I think your original intention here is?