Hypersistence-Utils and PostgreSQL support the use of multi-dimensional arrays.

@Type(value = FloatArrayType.class)
@Column(name = "data", columnDefinition = "real[][]")
private float[][] data;

Tested using

org.hibernate.orm:hibernate-core:6.5.3.Final
io.hypersistence:hypersistence-utils-hibernate-63:3.8.3