Use references to reuse paths for task symbols

Hi there,
I just noticed, that you have a copy of the SVG path that describes a symbol of a task in every task of this kind. That leads to a much larger SVG code than necessary. Is there anything that speaks against using the SVG referencing mechanism? You declare the symbols once in a <defs> part at the beginning and then reuse them whereever you need in the diagramm <use xlink:href="id"/>.
http://www.svgbasics.com/defs.html
I thought that would be common practice? Are there browser compatibility issues with this approach?
Regards
René

Example of path for hand symbol in manual task
<path d="m 17,15 c 0.234,-0.01 5.604,0.008 8.029,0.004 0.808,0 1.271,-0.172 1.417,-0.752 0.227,-0.898 -0.334,-1.314 -1.338,-1.316 -2.467,-0.01 -7.886,-0.004 -8.108,-0.004 -0.014,-0.079 0.016,-0.533 0,-0.61 0.195,-0.042 8.507,0.006 9.616,0.002 0.877,-0.007 1.35,-0.438 1.353,-1.208 0.003,-0.768 -0.479,-1.09 -1.35,-1.091 -2.968,-0.002 -9.619,-0.013 -9.619,-0.013 v -0.591 c 0,0 5.052,-0.016 7.225,-0.016 0.888,-0.002 1.354,-0.416 1.351,-1.193 -0.006,-0.761 -0.492,-1.196 -1.361,-1.196 -3.473,-0.005 -10.86,-0.003 -11.0829995,-0.003 -0.022,-0.047 -0.045,-0.094 -0.069,-0.139 0.3939995,-0.319 2.0409995,-1.626 2.4149995,-2.017 0.469,-0.4870005 0.519,-1.1650005 0.162,-1.6040005 -0.414,-0.511 -0.973,-0.5 -1.48,-0.236 -1.4609995,0.764 -6.5999995,3.6430005 -7.7329995,4.2710005 -0.9,0.499 -1.516,1.253 -1.882,2.19 -0.37000002,0.95 -0.17,2.01 -0.166,2.979 0.004,0.718 -0.27300002,1.345 -0.055,2.063 0.629,2.087 2.425,3.312 4.859,3.318 4.6179995,0.014 9.2379995,-0.139 13.8569995,-0.158 0.755,-0.004 1.171,-0.301 1.182,-1.033 0.012,-0.754 -0.423,-0.969 -1.183,-0.973 -1.778,-0.01 -5.824,-0.004 -6.04,-0.004 10e-4,-0.084 0.003,-0.586 10e-4,-0.67 z" style="fill: white; stroke-width: 0.25px; stroke: black;"></path>