If I used the default installer the networking was not working after conversion (with ifupdown probably, yes). So I compared the manually installed packages list in the starting and the converted image and looked for network related stuff, netplan was the one that seemed fitting and leaving it solved the problem.
This serial console is the one used by qemu, I don’t know about other virtualization solutions.
I’m not sure what acpi is for, probably shutting the vm off from the host? Yes, it does not seem to work and would be useful.