The Oppo 105D can be used as a USB DAC (plugged into a computer running Roon) but is not Roon Ready (it can play audio files from a network, but not via Roon’s interface). The new Oppo Sonica DAC supposedly has Roon Ready in progress but it is not going to be included on its initial release. Presumably either could be plugged into the Macbook via USB.
Depending on the Synology NAS you have, you may be able to run Roon server on it. If it has a 32 bit or otherwise underpowered CPU then it can only be used for storage, accessed by whatever you’re running Roon on.
The 105D is now discontinued, is unavailable directly from the company, and is selling for ridiculous prices on Amazon and eBay. It doesn’t look like they plan on releasing a new disk player with a premium audiophile quality DAC built in. I had thought of picking one up since my BDP-95 cannot be used as a USB DAC and my Benchmark only does up to 96K samples/second via USB, but it looks like now I’ll have to discontinue that plan, at least until the market for 105D’s settles.