Either the first or last selected item could be the reference point for aligning to center
Right now all items jump around when center aligning multiple items. It might be nice if either the first or last selected item stays in place and have the other items adjusted to it, as to have more control over the layout.
Vasileios Pothos commented
For anyone need alignment based on Last selected element (which is something I really need as I align in this way graphics in other software), he can install and use my plugin from the following link: (Extensions manager -> Install from Url -> add the following Url)