I have two comments on that. One is: assuming that you are right, it still makes a practical difference what kind of formlessness is the "final" layer, specifically, whether it is available for conscious experience or not. For example, in the Advaitic paradigm the ontic prime is pure formless Awareness which is directly available for experience, so we can not only intellectually grasp it, but also spiritually experience the pure awareness in a mystical experience. That makes it very useful for spiritual practice because we can develop an advanced state of consciousness where we are continuously aware of the ceaseless presence of the formless awareness (nirvkalpa samadhi in the Vedic tradition). However, that is not possible if the final formless ontic level is prior to awareness, in which case we can only intellectually grasp it, but never experience directly, it would be a Kantian "thing in itself" for us (only that it is not a "thing").         Another comment: in some schools of the Buddhist tradition, as well as in modern philosophy, there is an anti-ontological approach, which is that there is no such thing as an ontological prime whatsoever, there is nothing in the world more fundamental to anything else. Basically, the idea of ontology is based on a premise of causality: when we see facts or events or forms, we search for the cause of them. This is helpful in our survival to understand casual links between events, so it is basically a cognitive survival mechanism. But the point is that our principle of causality is an idea derived from observation of correlations between events (forms). Then, in philosophical or spiritual enquiry, we also apply this principle of causality to try to understand how the world is structured in general on the cosmic scale. In this case we try to find the "prime cause" to which all events and forms can be reduced and from which they can be derived. Obviously, this reduction to the cause cannot be run indefinitely and at some level must reach a "bottom" which we call the fundamental "ontic prime" which by itself is not caused by anything else more fundamental to it. This is basically a reductionistic idea commonly used in both physics and ontology. However, there are legitimate doubts that this reductionistic idea is applicable to the world as a whole. What makes us think that the principle of causality that we developed from observations of phenomena is applicable to the nature of things? What if there is no fundamental ontic prime whatsoever? This anti-ontological skepticism was entertained in some Buddhist schools. For example, if you read the Heart Sutra, it says "form is emptiness[formlessness], emptiness is form, form is no other than emptiness, emptiness is no other than form", in this equation formlessness is not more fundamental to forms, but they are ontologically equal and inseparable. This is also the Zen approach. Indeed, if we enquire into the raw bottom level of our direct conscious experience, there is an experience of a wholistic "blob" of the stream of forms/qualia each of them inseparable from the suchness-awareness of them (with the "experiencer" nowhere to be found). Or it can be a state with pure formless awareness with no forms, although arguably there is still memory as form present (otherwise we would not be able to recollect such experience). But why do we have to assume that the formless awareness is necessarily more causally fundamental to forms? The usual argument is that awareness is changeless and ever-present while forms are impermanent, they come and go. Awareness is uniform and boundless while forms are variable and have boundaries. So what? Is that a sufficient reason to assume that formless awareness is causally fundamental to forms? I'm not so sure about that.