<use> and <symbol> have been an integral part of SVG for yonks. I remember it working robustly even in Adobe SVG Viewer days (my Dad made extensive use of them

<use> and <symbol> have been an integral part of SVG for yonks. I remember it working robustly even in Adobe SVG Viewer days (my Dad made extensive use of them in some software), and although some small details have changed concerning how interaction-based styles apply (:hover and the likes) it’s always been dependable.