One of the young leaves in photo 3 has edges rolled under, which makes it aculeata rather than longifolia, whose leaf edges are flat to curved down. However, the leaves appear to be a bit wide for aculeata. According to Plantnet, aculeata leaves are up to 2 mm wide, while longifolia leaves are 2-6 mm wide. Please comment.
The leaves are 2mm max. There are other Cassinias in the area that are not in flower yet and that have narrower leaves, about 1mm. I don't know if they are the same species.
Almost certainly aculeata with a leaf width of 1 mm. Check the backs of the leaves. If aculeata, they will be rolled down, and at 1 mm wide, the surface of the back of the leaf could be completely obcured by the rolled margins.