I run an unraid server and there's a docker app built by someone in the community that makes it easy to spin up a macos VM (called macinabox). So that's what I used. It's basically a pre-canned way to booting opencore, downloading macOS iso, and mounting everything so that it installed on the VM disk.

It's kinda flakey and i had to update opencore before it became stable. so far so good. crossing fingers.