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.

never heard of airmessage. but i think functionally it's similar, Except bluebubbles has a windows client which I end up using.

I just got bluebubbles server running on a bigsur VM and it’s been running without issues for the last week. Seems to me way more useful than phone link.

I highly recommend it.

https://bluebubbles.app