Seems like the community of Zcam users is growing and Zraw is not well supported by NLE yet. It might be an area where Vegas can corner the market. At least for a while. I would appreciate at least a decoder, I'm not sure I would render to Zcam. I hear Zcam is very approachable for support to developers.
It wasn't that great the 1st time I looked at it but the newest alpha version of the Zraw Parser is quite good. Maybe better than the official Zraw Converter... it's certainly way faster. It apparently just re-wraps the lossless-hevc content in the zraw container and puts it into a container-less file with a ".avc" file-type (it's content is actually hevc). I was able to turn that file into a video clip that Vegas can read with this ffmpeg command: