The first restriction is severe. Identity is not treated as primitive. Objects, values, labels, and classifications are therefore not allowed to sit at the base as already assumed accessible primitives. They have to become available through the derivation.
Let us take the example of baryons.
To take the non-essentialist claim, that identity is not primitive, one has made an ontological argument, and thus from ontology, the only real test is to see if one can reach fundamentality. Not just qualitatively but quantitatively too. Baryons remain among the most well documented, rigid, and yet historically among the hardest to predict of fundamental structures. Each one as an object holds a large amount of structure that would have to be recovered from a relational description alone. They have charge, mass, family placement, spin-partner structure, radius information, and decay ordering. What happens if we do not assume intrinsic masses? That too would be a primitive identity, a fact before relation that determines the organisation of the spectrum. Can the organisation be recovered by something simpler? Something without such input variables? The question may first seem quixotic, but if the commitment to non-essentialism is possible. Then this is a step we must explore. So, if a non-essentialist ontology is to meet physics, it should do more than describe relation in qualitative terms. It should open a quantitative route.