I ask myself if using 4Kn HDD inside a NAS through iSCSI (Synology DSxx15+) has the same restriction (unsupported) as using 4Kn drives as for local storage?
Support statement for 512e and 4K Native drives for VMware vSphere and VSAN (2091600) | VMware KB
I am not 100% sure but I guess iSCSI has the same restriction (blockbased access encapsulated into TCP protocol)...?