Many properties only obtain via the interactions of many parts/relations. — Terrapin Station

I'll try to explain better. I've forgotten some of the technical terminology so bare with me.

Aren't properties themselves supervenient on their underlying structure? It seems off for something that is fairly interpretive would have a phenomenal ontological frame of reference.

And even if not (properties not supervenient), it seems odd from an action philosophy perspective too in that an abstract frame of reference of being the thing in question would have physical interaction.
For example: a basin draining water would have countless frames of reference: below the basin, right side of the basin, but the frames of reference wouldn't have a physical effect on the water, in themselves. Whereas with consciousness, it obviously generates endless discussions (like this one).
So if the frame of reference is a vital part of the equation then it includes it having a physical effect.

I think I understand what you're asking better. Thanks for the added explanation.

The whole point of my view is that talking about the properties of the water in the basin, to use your example, has to be done from some reference point/reference frame (I'm not using reference frame just the same as it's used in physics, just in case someone would think that I am), and talking about it with respect to "the water itself" is just one reference point/frame out of a potential infinity of them, with it not being a preferred reference frame (since there are no objective preferences).

So yes, properties are supervenient (if you like--I think that term can introduce some confusion) on underlying structure, but the underlying structure is "everything in the reference frame." It's only "just the water" from the reference frame of only the water, which isn't a preferred reference frame. (Not that It's not-preferred compared to something else, either--again, there are no objective preferences.)

So, for example, a coin really is round from some reference frames, and it's really oblong from other reference frames.

The idea is a bit like perspective in visual art. Assuming we're trying to do something like realism (or photorealism), the properties of the items depicted will depend on the focal point of the image. From most angles, you can't draw a coin as something round, because it's not really round at that focal point, it's oblong. Or, the coin might really be as large or larger than a mountain from some focal points. That's not an illusion. It's really the way things are at that focal point. The underlying structure is everything in the reference frame, not just the coin, but the relative angle at that focal point, the lighting at that focal point, etc. And on, in, just above etc. the coin are all just different possible focal points.

Focal point, by the way, doesn't imply a sentient creature's perspective. It's simply what things are like (in particular respects that we can represent visually in this case) relative to a particular spatio-temporal points. We can illustrate this sans sentient creatures with any machine that can measure properties from particular spatio-temporal locations--like a camera, for example.