Nice anatta observation. Yeah, it's really easy to hear the words "things are where they are, as they are" and "in the seen, only the seen" and hear it as a normal "this seeing that over there from here". But the extra effort of maintaining over here and over there is... extra.
But many many times throughout the day -- maybe 10,000 times -- everyone will have experiences without a coordinate system... but we rarely recognize them. Usually it's only during sports, or sex, or eating, or meditation that the kind of no-coordinate system experience is noticed. But it's really just a matter of walking around and noticing how experience happens (and this is why walking meditation is as valuable as sitting meditation).
Once this starts becoming obvious, how many experiences happen without a coordinate system, then you can bring back even the coordinate system. A big spiritual mistake is to assume that anything that creates a sense of duality is wrong. But this is a very simplistic and ignorant view that can trap people. It's important to see that there is nothing wrong with having coordinates, but.... the assumption that there is a solid thing at the center of the coordinates that needs protecting, well that's the original ignorance, the origin of suffering. There is nothing solid at the center. And when you go to "look" for the solid thing, you've created a another coordinate system, which is fine, but there is nothing at the center of the new coordinate system that is trying to look at the center of the old coordinate system.
Noticing how the assumed coordinate system's center keeps moving can be another great meditation, sitting or walking. And you can key into how effortless life is when the coordinate system is allowed to go where it wants.
The assumption of self and the paranoia of needing to protect the self sort of lean against each other and if either are seen clearly for what it is, the whole thing collapses (the ridgepole breaks), the knot unties...
The main challenge is that when the sense of something solid in the center starts to weaken... a very subtle and primal fear will arise. Definitely. It's the fear of anniliation, death of the self. The practice will seem a bit wrong and dangerous. (Which is yet another experience with a coordinate system that has nothing at the center of the coordinates.) The main role of a teacher/mentor/guru at this stage is to help someone stay in this uncomfortable zone using various practices, but make sure they are challenging themselves and really feeling this very very subtle discomfort. (And to warn them about the killer cows, a very important part of the sutta

) And it's not like a meditator really needs to be forced or pushed by the teacher at this point, it's more like a non-verbal communication that it's okay to do practices that seem a bit wrong and dangerous, yet we are really really interested in where it seems to be leading.
“Then, Bāhiya, you should train yourself thus: In reference to the seen, there will be only the seen. In reference to the heard, only the heard. In reference to the sensed, only the sensed. In reference to the cognized, only the cognized. That is how you should train yourself. When for you there will be only the seen in reference to the seen, only the heard in reference to the heard, only the sensed in reference to the sensed, only the cognized in reference to the cognized, then, Bāhiya, there is no you in connection with that. When there is no you in connection with that, there is no you there. When there is no you there, you are neither here nor yonder nor between the two. This, just this, is the end of stress.”
https://www.dhammatalks.org/suttas/KN/Ud/ud1_10.html