This video shows how you can attempt to maintain symmetry in your Warp Feature edits.
It is unfortunate that we have little control over the marque but you can use reference geometry as a visual reference.
In this case, the extrude feature has geometry points that extrude to axes.
Also notice the repositioning the narrow edge based on the original marque rather than an axis reference.
Selecting nodes is done by selecting the 1st node and using the CTRL key to select additional nodes.
Selected nodes are green; highlighted nodes are dark red; symmetry nodes are bright red, when using the default color scheme.
This is only one way to use this feature. This technique is only one of many that could be written for a Warp edit.
Enjoy.
...Remember to use the HD setting for a clearer view.