Synology suggest website to ask them to test a device for the compatibility list.

[Mokar]

I opened a ticket at Synology asking if they want to test the Seagate Exos X20 20TB ST20000NM007D HDD

They replied asking to make the suggestion here synology.com/en-global/form/suggest_device

I don't know if you know this ?
Other thing is maybe to help submit, this way if they get a lot off requests they maybe do something.

[ed]

That's true. I hope people find this post and do submit their requests.