Disclaimer: I’m not representing the official opinion of any organization here but merely thinking out loud to push the discussion forward 
I’m also mindful that most of these questions have received attention elsewhere in the forum (for example here), so my apologies for the bits that reflect my lack of knowledge of past discussions.
Okay, let’s make this a bit more concrete. I understand that you raised a question but have not yet come to a conclusion. Do you think the ZF board should not include individuals who are or have been affiliated with the ECC? It appears to me that, were such a rule introduced, it should apply equally to all development teams working on Zcash, because otherwise it would amount to special treatment. In other words, do you think all developers (except for those employed by the ZF) should be excluded from access to the ZF board? If not, how would you distinguish between those who should have that right and those who should not?
Given it’s stated role, perhaps the ZF should instead be open to the community as a whole, including developers? I’m not saying the concerns you raise are irrelevant or unfounded as I’m sure we can all agree that the ZF should not be “captured” by any single interest. But maybe, instead of singling out concrete organizations or groups of people and denying them a voice in a structure that is arguably central to the strategic governance of Zcash, perhaps we should instead aim for a good balance of power?
Instead of “absolute independence” from the influence of concrete groups or organizations, for an organization like the ZF, perhaps a more appropriate goal would be to be “maximally dependent” on and inclusive of as many stakeholders as possible? Put differently, isn’t the ZF exactly the kind of meta-structure that should bring together all viewpoints and serve as a platform in which different interests can agree on what’s good for the ecosystem as whole, all things considered? I’m just throwing it out as an idea. I’m sure different people have different opinions on this, but before there’s general consensus on what the ZF is and/or should be, it’s difficult to discuss how it should be governed.