One thing that doesn't seem to be entered into people's conversations about the value of having kids is value of information.
There a common thought that Effective Altruists can, through careful, good parenting, impart positive values and competence to their descendants. However, it is highly uncertain how well this will actually go. And given the large differences in cost-effectiveness from top causes to secondary ones, and from Effective Altruism to other social movements, it is pretty important to know how likely our kids are to remain faithful to Effective Altruist principles. Yes there is existing evidence on parent-child transmission of other social movements and religions, but who knows how well it will generalize.
Answering this question within 2-3 decades would provide significant value to future Effective Altruists about whether they should have kids.
Of course, the importance of this consideration depends greatly on the expected size of the EA movement in the future.
For the record, I wouldn't describe having children to 'impart positive values and competence to their descendants' as a 'common thought' in effective altruism, at least any time recently.
I've been involved in the community in London for three years and in Berkeley for a year, and don't recall ever having an in-person conversation about having children to promote values etc. I've seen it discussed maybe twice on the internet over those years.
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Additionally: This seems like an ok state of affairs to me. Having children is a huge commitment (a significant fraction of a life's work). Having children is also a major part of many people's life goals (worth the huge commitment). Compared to those factors, it seems kind of implausible even in the best case that the effects you mention would be decisive.
Then: If one can determine a priori that these effects will rarely affect the decision of whether to have children, the value of information as discussed in this piece is small.