The only problem is that no mock-up behaves like an orchestra. Note that I didn’t say ‘sounds’ like one - it’s possible to make some great sounding mockups. But in (for example) Dorico with Noteperformer that involves a lot of odd tweaking of dynamics and articulation (and sometimes doubling or removing parts) just to get it to sound like an orchestra would at say ‘mp’. If you don’t know that and just write ‘mp’ you’ll get a shock when it goes in front of a band.