Nadia suggests a theory in the last footnote of her post, "that projects only need to define governance at the first sign of conflict". Intuitively, this makes immediate sense. We have all seen the projects which seem to work very fine without any thoughts about governance, and we also have seen those projects where attempts to set up formal governance have brought things to a halt instead of serving the project. So doing it at the last responsible point in time, when you actually need it, sounds like a very attractive model.
Being able to add governance on demand needs a high level of awareness and reflection. It also needs a culture which is open to the idea of governance, has the means to facilitate discussions about it, and is able to come to a conclusion. It is the point where you have to "decide to decide".
This is not easy, especially in the context of a conflict. It can be paralysing. Making decisions without having defined structures, without having precedence, takes responsibility and courage. Maybe not everybody will go along with it. You don't know because you haven't done it before.
One model which seems to be a quite natural outcome of such a "we need governance, now" situation, is the "benevolent dictator". When conflict arises, the founder or another exposed person steps in and takes a decision. This sets a trajectory for the project, which might be right or not. It depends on the project, on the people, on the environment.
Another model which comes naturally is to follow the "those who do the work decide" principle. This adds local, high context governance. It has to be underpinned by common values and a common sense of direction, though. Otherwise it will fail to solve the kind of conflicts where active people seem to stand against each other.
If you have a strong culture, it might appear you don't need governance. If you have shared values, if you have a common mission, if people learn by imitating healthy behavior from others, then it's easy to take decisions and to preempt conflicts. This could also be called a state of implicit governance, because it is there, but it's not formulated.
If you have a strong culture, then you are also prepared to add governance on demand. This can become necessary because of growth, a changing environment, or other factors which can't be addressed by existing intuition.
From this point of view: Build culture first and governance will follow.
These are my thoughts. I would be more than happy to hear about your thoughts as well.
Foot note: In some way "governance on demand" is not a governance model in itself, but more a meta model. It doesn't tell how the governance regarding the project then has to look like but only answers a part of the question how to get there. It is in the nature of governance models to also cover this meta level, though. Maybe "governance on demand" is more a governance element than a model in itself. It governs the evolution of governance models.