A quick note for myself:
Raspberry Pi hangs on “a start job is running for lsb no limit” – this is the network interface manager trying to start up its connections. If you have interfaces listed in /etc/networking/interfaces which do not exist, you might see a timeout or delay here.
Solution: create a new file (and possibly folder if needed) in /etc/systemd/system/networking.service.d/reduce-timeout.conf
[Service] TimeoutStartSec=5
This will drastically reduce the starting timeout for interfaces. I haven’t tested in detail, but it looks like new interfaces will still load normally after boot.
Worth noting that systemd first looks in /lib/systemd/ for various default configs, then looks in /etc/systemd/ for additional configs, before merging them all. The exact chain of configs as applied can be seen by running systemctl status networking.service