Windows -> macOS remote desktop - can it be emulated just as good as Windows -> Windows?

So I've just installed Big Sur in a VM on my unRAID server. Works flawlessly and iCloud/iMessage works as well.

My problem is, I want a somewhat similar experience doing remote desktop into the server, as I would if I use native RDP in Windows, when I connect to another Windows machine. My Windows/daily driver setup consists of 3 monitors (4K, 2.5K, and 2K), but if I remote desktop into a Windows laptop with only a single 1080p monitor, it automatically emulates 3 monitors for me, exactly like it is in my daily driver Windows setup.

However, I have not gotten that to work when doing Windows -> macOS. I have enabled GPU passthrough and removed VNC in virt manager, so I need to have a monitor attached to my unRAID server's graphics card, in order to get a resolution.

Is it true there is no alternative method out there? Preferably I would love to run the server completely headless, but I do have some HDMI 4K dummies/emulators coming soon, if I really need to use those.

I just want my 3 monitors on my Windows setup to show a macOS desktop with 3 monitors as well.