vArranger is more a live real time arranger, so no need to connect with the DAW.

When you want to compose or sequence, you simply export your vArranger SONG CHORDS to Midifile, and then start working on your DAW, so I don't really see the point of Rewire for vArranger

From what I have seen, the steinberg generic asio has tons of latency

some sound cards allow multi client ASIO drivers