Just got the email that a question came in. Yes, they work! Since Synology started selling its own hard drives, the compatibility list is only of limited use. For some devices, there are a few storage media that are explicitly incompatible (other list!). I would urgently keep my hands off these. The common NAS and enterprise hard drives (e.g. the Exos X00 series) are usually compatible. However, Synology support will probably refuse to help with reference to the hard drives.

In der Kompatibilitätsliste https://www.synology.com/de-de... wird eine Festplatte aufgeführt: HAT5310-18T. Der Preis liegt bei 699 Euro.

I guess that's settled - they're on after all.