Foundations, like OpenSats, are very top down. Their managers decide how to award grantees. Associations are generally bottom up. The presence of official members creates a different sense of accountability for each member and more discussions on the right use of the money.
Its just a very different way of doing the same thing.
Having a protocol for membership to specific projects, or rather just any Nostr account, I think would be valuable. The account could be an association that, as you have mentioned, has engineers contribute to multiple projects. It could also be to a project that works specifically on a set of projects, or single project, that they maintain.
Also useful here would be to have issue tracking and private support tickets as part of the protocol that is dedicated for members. Thus priorities can be determined based on that feedback.
