By the phenomenological stance I mean that I believe the world is only known through experience. This reduces down in terms of physics to something like "all information is generated by observation" where "observation" is the technical term used to mean the sort of physical measurement we encounter in quantum physics where entropy is generated. If there is anything more going on that's fine, but we still won't know about it except through the standard process by which classical information is generated.

By the existential stance I mean simply that I believe the world exists first. This seems sort of obvious, but the alternative is essentialism, which assumes there is some structure to the world that determines its existence. The question is which comes first, ontology or metaphysics. Existentialism says ontology comes first, and through ontology we can discover metaphysics. Essentialism says the opposite, that metaphysics reveals ontology (naturally for this reason metaphysics and ontology are often not clearly distinct in essentialist perspectives).

I think it's worth noting that both these perspectives are often only nominally or shallowly respected. I think a lot of this is because the phenomenological stance implies that we only have an inside view, and any "outside" view of the world we obtain is necessarily an inference from our inside view of the world. But it's quite easy to accidentally conclude the outside view we've inferred is timeless (this is, after all, seen by many as the entire point of philosophy: to discover timeless truths), so there is a risk of short circuiting both phenomenology and existentialism to produce ontological realism and essentialism, respectively.

I believe the combination of these two is necessary. Accepting the phenomenological stance we are forced either into Husserl's idealism and transcendental phenomenology or realism. Since idealism makes untestable claims, even if it is true I can't really say much about it, so I must take the realist stance. And based on my knowledge of the world, I'm forced into existentialism because I can find no strong evidence that there is a structure preceding existence and there seems no evidence suggesting a real world does not exist (solipsism). Existentialism is basically what's left after eliminating the possibilities that don't fit the evidence.

To summarize, I take the view that things exist prior to knowing about them, and the only way we know about them is through experience.

The consequence of both on my epistemology is that I have no conception of "truth" as the world is normally used. The only recovery for "truth" is something like correspondence theory but through the lens of phenomenology, so I can at most say I have knowledge that leads me to believe a statement has some likelihood of corresponding with reality but only insofar as I can observe the correspondence through experience. We cannot even talk about the "true" probability that a statement corresponds to reality, since doing so introduces a side channel for gaining information that is not through experience.

So where this leaves me with morality is that I must naturally reject moral realism in the sense that there are no true statements, let alone true moral statements. I further don't find notions of "good" and "bad" meaningful because linguistically they imply a moving of meaning from strictly residing in the ontology to being part of the metaphysics, thus they make poor choices for technical terms for me because of their connotations.

What I can say is that there are intersubjective beliefs about reality and those inform our preferences and it is our collective willingness to hold certain preferences and categorize those preferences under labels like "good" or "bad" that creates "morality", but this morality is strictly speaking only resident in ontology and seems to imply little about metaphysics.

I'm not exactly sure what to call this metaethical stance. It's not quite moral nihilism or non-cognitivism because I'm not wholly rejecting the notion that we might come to agreement on particular preference norms, but it also seems not moral realism or cognitivism because the place where there is agreement to come to resides in experience, and thus ontology only, not the external reality of metaphysics that exists outside experience.

Perhaps this should be classified as moral realism? Although doing so to me seems to lump it closer to theories it is more dissimilar from, whereas it is fairly close, especially in its application, to moral nihilism, except that it is grounded in the intersubjective rather than simply not in the objective.