I doubt it since they have their own way of handling geo in the viewport (pixols) that probably wouldn't translate well for a 3rd party renderer. The alternative is exporting and rendering outside of Zbrush, like Keyshot.
The renderer in zBrush is pretty good as well as the BPR system. I only tested out Keyshot for a little while but was very impressed with it. Like oglu sed using it is pretty seamless and the quality high. Probably a standard 3D artist needs a swish renderer, but most of us never use it in zBrush as our interest lies in…