Hi David,
I summarised my understanding of the architecture in this post, which may assist in understanding zones etc.
I don’t believe there are any other adjustments you can make within Roon that will affect SQ. I prefer to disable volume rather than force max, because it is more minimalist, but I don’t hear a difference between them.
Roon will soon be partially integrated with HQPlayer, which enables upsampling and a variety of digital filters to be used in substitution for the filters in a DAC. HQP also supports a room convolution engine for real time EQ. Those will be the next features directly relating to SQ.
Edit: I understand (thanks to Richard) that Roon can send output to AsQ+ but not Symphony.