There are a whole host of issues to consider. When you undertake a process of that sort, tradition, for example written tradition, becomes an issue. Agreeing on a set of symbols means dropping others. And sometimes it's difficult to compromise. We face the same difficulties in French. One of the hot topics when the French-language CBFU was adopted was figures. The recommendation is that Antoine figures be used. In Canada, two kinds of figures are used: Louis-Braille and Nemeth figures. In Quebec, the latter were used. One issue was that in France, Antoine figures were used.
On February 24th, 2009. See this statement in context.