Working on SQLEditor SVG improvements (arriving soon in 3.0), and found this excellent series of articles by Sara Soueidnn on several of the details.
So SQLEditor in future will be using the same object icons in SVG as are drawn in the main document and each will be its own beautiful SVG symbol, rather than being separately drawn.
(Object icons in SQLEditor 3 are now little images rather than being individually, because this improves performance quite noticeably and allows nicer styling)