I don’t assume that macOS virtualization is advanced enough to support memory ballooning, or is that not what you’re referring to?
Edit: I stand corrected!
macOS is generally pretty amazing at efficient memory usage and VM (virtual memory subsystem) handling. So even a 8GB machine can run pretty impressive workloads without having the user think the machine is underpowered.
What will that help with if the host and guest combined need > physical ram?
I don't assume anything either, but a single Google search is enough to dispel that [1]
[1] https://developer.apple.com/documentation/virtualization/vzv...