Under the District's upcoming Performance Management system, schools with strong results will be granted more autonomy. You may wonder what this means in real terms.
It occurs to me that any school where the pass rate on the math WASL is 80% or better should have the freedom to choose an alternative math textbook. North Beach is already doing it, so there is a precedent. In fact, I presumed the 80% pass rate requirement because that's about the pass rate at North Beach. It also occurs to me that it should be easier if an elementary school wants to use the Singapore math books since the District did adopt the Singapore series and does claim to support it.
Let's say that you have a child at one of the many elementary schools where the pass rate on the math portion of the WASL is 80% or better. Let's say that you are dissatisfied with the Every Day Math texts and the reform/investigation/discovery/constructivist pedagogy dictated by those texts. You could seek support within the school - probably starting in the PTA - for a change in the math education at that school, replacing the EDM books (and pedagogy) with the Singapore series (and teaching style). If you can convince the principal to make the change, the District should not oppose it. The District shouldn't oppose it because, under the performance management system, the school should have that freedom. Moreover, the Singapore series was approved and adopted by the Board.
I think you would have a real chance for success in your campaign. First, if the school's pass rate is that high, that means that the school community is probably a well-educated community that generally support education and are involved in their children's learning and are probably affluent. The families are probably well-informed about the math controversy and probably would support a more traditional style of education. You could get a lot of community support for the change. Moreover, at these types of schools the administration and staff are generally more responsive to the community they serve. Also, the school will have to pay for the textbooks and that will take the kind of PTA money that affluent schools can deliver. I know that's a lot of generalities and stereotypes, but let's all just acknowledge that the correlations are high.
There is already North Beach. That makes it easier for the next school. That school, once they have made the switch, will make it easier for the third and fourth schools to do the same. After the change, there is no reason to believe that the WASL pass rates will decline. If the movement spreads it may come to pass that a significant number of the higher performing schools will be using Singapore or some traditional texts and pedagogy. After a few years there will be a new Board, a new CAO, and a new Math Director, none of whom participated in the selection of EDM and have no pride tied to it. To them it will be obvious that the high performing schools are using the traditional texts while the low performing schools are using EDM. They won't know which is the cause and which is the effect and they may make the switch over to Singapore for the whole District.
Once the elementary schools are using Singapore, alignment will practically demand that the middle schools adopt a traditional text as well. Then the high schools will fall in line, too.
I don't know what the chances are to bring change in math pedagogy by trying to influence those in District leadership, but it doesn't look very promising to me. I think the better chance for success is at the grassroots.