The amount of work required is not that bad, how big is your library?

Whether you want the data on a NAS (which does not have to be QNAP, it is Meridian that only support QNAP NAS units) or an external USB disk attached to your server is your choice.

I would export to native format on an external drive from Sooloos and leave the Sooloos data intact on your MD600 so you have an option to switch back if you so choose. Then attach the external drive to your Roon server of choice and watch it build your library. I wouldn't personally use the MD600 as a NAS as there are much better solutions available for not much money YMMV.

Russ