Luckily, it's an easy fix
Apparently the installer adds both interfaces to the netplan, so it happily waits for DHCP to assign a network address for the full two minutes (even if there's no ethernet cable attached)
To fix, edit /etc/netplan/00-installer-config.yaml and remove the interface you're not using.
For example, the file contents will look like the following:
Since there is only a network cable connected to 'enp2s0', we can simply remove the 'enp3s0' lines. (note: only changing the dhcp4 value to 'false' does NOT resolve the issue, removing the lines does)# This is the network config written by 'subiquity' network: ethernets: enp2s0: dhcp4: true enp3s0: dhcp4: true version: 2