Roon remotes (and endpoints) can’t connect to Roon Server when the host machine is in standby.
If you did ‘hibernate’ the Roon server software and allow the NAS to go to standby, then, you would not be able to connect a Roon Desktop/Remote/ARC to the server until it was explicitly woken up (e.g. with a WOL packet sent from another application or manually).
Most people want their Roon Server to be available whenever they feel like some music - and having to explicitely wake up the server beforehand would be an inconvienience that they don’t want. Ironically, I would imagine that this is one of the major drivers for supporting Roon On NAS - because the NAS is often the one device in a household that is already turned on 24/7 and, in this case, the additional energy cost of running a Roon Server becomes negligible.
It has been suggested that the ability for a Roon desktop/Remote to wake a Roon Server using WOL be added. I suggest you add your vote to the feature suggestion if it is important to you. It can be found at:
However, it should be born in mind that not all Roon Servers support WOL.